When we look at EO and RC, we see three ways to approach their teaching. One is the logical order in which their doctrines are put together. The second is the historical ways in which these doctrines developed. And there is the existential or conversional meaning, what do people say made them convert. Many are raised in the Roman Catholic church with little understanding of what it teaches or the meaning of its rituals and how they contradict Biblical teaching.
The Logical Development of Doctrines within the Roman Catholic Church
The historical and theological trajectory of the Roman Catholic Church reveals a coherent, though deeply problematic, internal logic. It begins with the assertion that the Pope is the head of the Church, a claim that grants the institutional Church authority not only to determine the canon of Scripture but also to define its meaning.
This framework of authority facilitated the accommodation of pagan converts, a process that introduced a range of superstitious practices into Christian worship—statues, ritual observances, prayers to the dead, relics, and syncretized holidays—many of which are either directly contrary to Scripture or lack any biblical warrant.
The understandable desire for consistency and quality control among the clergy led to the emergence of a professional priestly class, formalized liturgies, prescribed prayers, and a liturgical calendar designed to instruct the faithful in Church history and doctrine. In turn, the desire to provide the laity with a clear, structured understanding of the Christian life contributed to the development of the seven sacraments as the normative means of grace. None of this is supported by the Bible, but the Roman Chruch looks to an oral and written tradition passed down by Church Fathers that is over the Bible in authority.
Liturgical worship, as it developed in the early and medieval church, bears a striking resemblance to pagan temple worship. When pressed on this similarity, advocates of liturgical practices sometimes appeal to the ceremonies of the Temple in Jerusalem as a model. However, all such Old Covenant ceremonies have been fulfilled and completed in Christ; they are no longer binding or normative for Christian worship.
In reality, liturgical forms were primarily accommodations to pagan converts, who were familiar with temple rituals and sacrificial systems. The most common defense of liturgical worship is that it served as a means to instruct largely illiterate populations. Yet this justification fails on two fronts: first, because much of what was communicated through liturgy incorporated elements foreign to Scripture or distorted biblical teaching; and second, because the appropriate solution was not to perpetuate visual rituals, but to teach the people to read the Scriptures for themselves.
This system was undergirded by sacralism: the belief that the Church should exercise authority not only in spiritual matters but also over the temporal affairs of the state, effectively ruling the empire. This vision culminated in the thirteenth century with the height of papal power, doctrinal formulations such as transubstantiation, purgatory, indulgences, and baptismal regeneration, and then after the Reformation the anathematization of Protestant reforms at the Council of Trent.
Monasticism as otherworldly withdrawal and the belief that celibacy is a higher spiritual state also flourished during this period, accompanied by increasing divisions among the various religious orders. In the nineteenth century, the trajectory continued with the dogmatic declaration of papal infallibility and the promulgation of the immaculate sinlessness of Mary.
Despite its claims to possess a visible, unified authority, the Roman Catholic Church remains deeply divided internally, a fact most clearly seen during the contentious processes of papal elections. The Church proclaims unity, but in reality, it is a fragile and often illusory construct.
Why Do People Say They Convert?
The appeal: That it is the original church, or it is the church of Peter who was made head of the church by Christ, or the church fathers taught what the Roman Catholic Church currenlty teaches, or the Roman Catholic Church has centuries of unity compared to Protestants, or the Roman Catholic Church was the only church for 1500 years and it gives the feel of tradition, reverence, and stability.
Although the Roman Catholics often begin discussions by agreeing that the Bible is our authority, we soon see they appeal to tradition when their practices either contradict the Bible or aren’t mentioned in the Bible. Their authority becomes “the church fathers” or what the Roman Catholic Church says the Bible must mean. This is a circular argument: how do you know the RC doctrine is true? It is what the RC teaches is true. A similar fallacy happens when they appeal to church fathers who are often taken out of context. We know that even in NT times false teachers rose up that needed to be corrected, or otherwise faithful apostles (like Peter) had to be corrected) and the correction for both was the Bible. That an early church father said something that contradicts the Bible should not surprise us nor shake us from making the Bible our authority.
The Historical Development
Roman Catholicism, as both a theological system and a historical institution, emerged from the ruins of the Roman Empire with a unique claim to universal spiritual authority. Over the centuries, the bishop of Rome—the pope—evolved from a prominent local leader into the spiritual head of Western Christendom, shaping not only the Church's doctrines but the course of European civilization itself. This transformation was neither immediate nor accidental. It was forged through crises and councils, emperors and monks, theological debates and political struggles.
The story of the Roman Church is a story of ongoing compromises with paganism. These compromises are rooted in failing to understand 1) the clarity of general revelation 2) the culpability of pagan beliefs about God and the afterlife 3) otherworldliness that hindered the discipling of the nations 4) corruption that crept in to protect the power structure used to push these beliefs into the world. These compromises began by saying we must accommodate new converts, but then end up with bringing in pagan idols. The yoke of Rome, with its calendar and holy days and sacraments, begins by saying we must teach the people, but ends up in obscuring the Gospel.
That they continue to put Mary before Jesus is seen in the last will of Pope Francis. Testament of “Holy Father Francis” 4.21.25 “I have always entrusted my life and priestly and episcopal ministry to the Mother of Our Lord, Mary Most Holy.”
I. Leo the Great and the Rise of the Papacy
As the Western Roman Empire crumbled under the weight of internal decay and external invasions, the Church of Rome began to emerge as the one stable and enduring institution in the West. At the center of this transformation stood Pope Leo I, later known as Leo the Great (r. 440–461), whose leadership marked a decisive moment in the consolidation of papal authority. Through a combination of theological clarity, moral authority, and political courage, Leo advanced the idea that the bishop of Rome was not merely a local patriarch, but the divinely appointed head of the universal Church.
Leo’s tenure as pope coincided with some of the most turbulent years in Roman history. Civil administration had broken down, barbarian tribes were advancing on Italy, and the imperial court had become weak and ineffectual. In this vacuum, Leo stepped forward not only as a pastor but as a statesman. His most famous diplomatic act came in 452, when he met Attila the Hun at the gates of Rome. While the details remain partly shrouded in legend, contemporary accounts report that Leo persuaded Attila to withdraw without sacking the city. A few years later, when the Vandals did invade Rome in 455, Leo again negotiated with the invaders to minimize violence and protect sacred sites. Though he could not save Rome from devastation, his actions embodied a new kind of spiritual-political leadership that would define the medieval papacy.
Leo’s leadership extended far beyond diplomacy. He was a theologian of great insight, articulating a robust vision of Christology that became central to Christian orthodoxy. His Tome of Leo, written in 449, offered a clear statement of the doctrine of Christ’s two natures—divine and human—in one person, a teaching that would be affirmed at the Council of Chalcedon in 451. In asserting this theological vision, Leo also strengthened the claim that the bishop of Rome possessed a special authority not only over doctrine but over the entire Church. He argued that the primacy of Peter, as the chief of the apostles, had been passed on to his successors in the Roman See, giving the pope a unique role as the guardian of unity and truth.
This assertion of papal primacy was all the more striking against the backdrop of the empire’s political collapse. As Roman emperors in the West faded into irrelevance, Leo claimed that the pope’s authority came not from imperial appointment but from divine institution. In this way, the papacy began to fill the void left by the disintegration of Roman government, offering continuity, moral leadership, and a new kind of Christian sovereignty rooted in the spiritual office of Peter rather than in imperial power.
This claim to apostolic succession and papal primacy, however, would later be strongly contested by the Reformers of the sixteenth century. Reformed theologians rejected the idea that Peter held a supremacy over the other apostles, pointing out that in Scripture, Peter is rebuked by Paul (Galatians 2) and shares authority with the broader apostolic body at the Jerusalem Council (Acts 15). They argued that Christ alone is the head of the Church, and that authority rests in the Word of God, not in an ecclesiastical office. For the Reformers, the Church of Rome had no divine right to supremacy; rather, the claims of the papacy were viewed as a corruption of apostolic simplicity and an illegitimate centralization of power. There is no reason to think that Peter was in Rome before Paul wrote the Book of Romans, meaning that Peter did not found the Church of Rome.
II. The Rise of the Papacy and the Seven Sacraments
The rise of the papacy as a central authority in the Western Church is inseparable from the leadership of Gregory the Great, who served as bishop of Rome from 590 to 604. In a time of political fragmentation and social instability following the fall of the Western Roman Empire, Gregory offered the Church a vision of stability, order, and spiritual leadership that would shape the role of the pope for centuries to come.
Gregory began his career as a Roman civil servant before renouncing public life and entering a monastery. His administrative talents, combined with deep spiritual conviction, made him a uniquely capable leader when he ascended to the papacy. As pope, Gregory assumed not only the role of spiritual shepherd but also civic administrator, overseeing the distribution of food to the poor, organizing defenses against invading Lombards, and managing the vast estates of the Church. Under his leadership, the Church in Rome became a kind of substitute government for the crumbling structures of the empire. In doing so, Gregory laid the foundations for the medieval papacy as both a religious and political power.
Perhaps even more influential was Gregory’s vision of the Church's mission and sacramental life. He emphasized pastoral care as the heart of Christian leadership, viewing the pope not as a ruler but as the servus servorum Dei—“the servant of the servants of God.” This pastoral emphasis extended beyond Rome through his commitment to missionary activity, most notably sending Augustine of Canterbury to evangelize the Anglo-Saxons in Britain and force them to join with Rome thus ending the Celtic Church. Gregory’s model of papal leadership—rooted in humility, spiritual discipline, and a sense of universal responsibility—became a template for future popes.
When Augustine of Canterbury was sent by Pope Gregory the Great, his mission was to re-establish Roman Christianity in Anglo-Saxon England, where paganism had taken hold after earlier Roman Christian communities faded. This mission eventually led to tension and eventual syncretism between Roman and Celtic practices—culminating in events like the Synod of Whitby (664), where Roman customs were adopted more fully by the English Church.
Alongside these developments, the early medieval period saw the gradual formalization of the Church’s sacramental system. While Christians had long practiced rites such as baptism and the Eucharist, it was in this era that the idea of seven sacraments as normative began to take hold. These included baptism, confirmation, the Eucharist, penance, marriage, ordination, and extreme unction (now called the anointing of the sick). Each sacrament was understood as a visible sign of invisible grace (God’s free and unmerited favor given in the sacrament), instituted by Christ and entrusted to the Church. They marked the stages of a Christian’s life and offered spiritual nourishment, forgiveness, and guidance.
The Reformed tradition sharply diverged from the Roman Catholic Church in its understanding of the sacraments—both in number and in purpose. While Rome affirmed seven sacraments, the Reformers recognized only two as instituted by Christ: baptism and the Lord’s Supper. These, they held, were not channels by which grace is infused ex opere operato (by the mere performance of the rite), but were instead visible signs and seals of God’s covenant promises, received by faith. Rather than being necessary rituals for dispensing grace, the sacraments were understood to confirm the faith of the believer and to nourish the soul by pointing to the finished work of Christ. In this view, the efficacy of a sacrament depends not on the act itself or the status of the officiant, but on the Word of God and the faith of the one receiving it. The Reformed rejected the notion that sacraments work independently of faith, and instead saw them as subordinate to the preached Word, serving to visibly reinforce what the gospel proclaims.
III. Charlemagne, Christian by Nationality, and the Holy Roman Empire
The coronation of Charlemagne by Pope Leo III on Christmas Day in the year 800 marked a watershed moment in the history of the Western Church and the redefinition of imperial authority. In a symbolic act of immense consequence, the pope placed a crown on Charlemagne’s head in St. Peter’s Basilica and declared him “Emperor of the Romans.” This event signaled not only the rebirth of a Western Roman Empire but the deep intertwining of ecclesiastical and political power that would characterize much of medieval Christendom.
Charlemagne—already King of the Franks—had expanded his dominion across much of Western Europe through military conquest and political alliance, but his imperial coronation by the pope conferred a sacred legitimacy to his rule. It suggested that the Church could crown emperors, and that Christian kingship was not merely a matter of political strength but of divine sanction. This moment inaugurated what would later be called the Holy Roman Empire, a trans-European entity that claimed continuity with the ancient Roman Empire, now baptized under Christian authority. This is called sacralism.
The relationship between the papacy and Charlemagne’s empire was mutually reinforcing. Charlemagne provided the Church with military protection, enforced religious uniformity, and supported ecclesiastical reform, including the spread of Benedictine monasticism and the correction of liturgical practices. In return, the Church offered the emperor moral authority, cultural legitimacy, and an educated clergy that could serve as administrators of the realm. This symbiotic partnership laid the groundwork for a medieval Christendom in which the pope and emperor stood as dual pillars of God’s order—spiritual and temporal.
Yet this alliance was not without tension. Though Charlemagne accepted the pope’s blessing, he did not see himself as a mere vassal of the Church. He saw himself as God’s appointed ruler, with authority to direct the Church’s reform and to convene councils. In practice, the balance of power between pope and emperor would ebb and flow across the centuries, leading to moments of intense conflict, such as the Investiture Controversy in the eleventh century. But the model inaugurated in 800 remained powerful: a vision of Christian society in which Church and State, cross and sword, worked together to establish the kingdom of God on earth.
In addition to his political and military achievements, Charlemagne undertook a sweeping program of cultural and religious renewal that helped lay the foundation for medieval European civilization. He invited the Anglo-Saxon scholar Alcuin of York to his court and established a palace school at Aachen, where the study of classical texts, Christian doctrine, and Latin literacy was revived—a movement later known as the Carolingian Renaissance. Charlemagne believed that a well-ordered Christian empire required educated clergy and literate administrators, and so he promoted the founding of cathedral and monastic schools throughout his realm. His commitment to Christianization extended beyond education to missionary efforts, often backed by military force. Following the example of earlier missionaries like Saint Boniface, who famously cut down a sacred oak tree revered by Germanic pagans, Charlemagne sought to bring pagan peoples into the Church—not only by persuasion but, at times, by compulsion. His campaigns against the Saxons, for instance, combined military conquest with baptism and religious instruction, reflecting his vision of a united Christian empire where political loyalty and religious faith went hand in hand. “Being a Christian” meant “living in a Christian land.”
This dual authority would later be explained through the metaphor of the “two swords”—one spiritual (wielded by the Church) and one temporal (wielded by the State). According to medieval Catholic doctrine, both swords ultimately derived from God but were entrusted to different hands for the governance of the world. The pope, by crowning emperors and excommunicating kings, claimed superiority even over temporal rulers. This theory of overlapping and hierarchically ordered powers shaped the entire political theology of the medieval West.
The Calvinist tradition would later offer a sharp critique of this model. While acknowledging the legitimacy of both civil and ecclesiastical authority, Calvinists rejected the idea that the Church should wield power over the State or that the pope had any divine right to crown or depose kings. In Calvin’s view, the “two kingdoms” or “two governments” were ordained by God for distinct purposes: the Church to preach the Word and administer the sacraments, and the civil magistrate to preserve order and justice. These two spheres were to remain distinct yet cooperative, neither usurping the role of the other. Calvinist political thought emphasized the accountability of rulers to God directly—not through papal mediation—and championed the authority of Scripture over both Church and State. In doing so, the Reformed tradition dismantled the medieval synthesis of throne and altar and called for a clearer separation of spiritual and civil power.
IV. Papal Supremacy and the Two Swords
The twelfth and thirteenth centuries witnessed the height of papal authority in medieval Europe, as the bishop of Rome claimed not only spiritual leadership over the Church but also supremacy over emperors and kings. This bold assertion of papal power was crystallized in two key moments: the Investiture Controversy under Gregory VII and the full development of the theory of the two swords under Innocent III. During this period, the papacy sought to shape the course of empires, reform the clergy, and present the Church as the supreme moral and political authority on earth.
The Investiture Controversy (late 11th century) marked a dramatic conflict between Pope Gregory VII and the Holy Roman Emperor Henry IV over who had the right to appoint bishops and invest them with symbols of office. Traditionally, emperors had exercised considerable influence in selecting bishops, many of whom held both spiritual and temporal power. Gregory, however, insisted that only the pope had the authority to appoint clergy and invest them with spiritual office. His decree Dictatus Papae asserted that the pope could depose emperors, convene synods, and that the Church of Rome had never erred. When Henry refused to submit, Gregory excommunicated him, leading to the famous scene at Canossa in 1077, where the emperor stood barefoot in the snow, seeking absolution. Though the conflict would continue for decades, the controversy permanently altered the balance of power in Europe, elevating the spiritual authority of the papacy above imperial control.
Building on this legacy, Innocent III (r. 1198–1216) reached the zenith of papal supremacy. A brilliant jurist and theologian, Innocent developed the full doctrine of the “two swords,” based on Luke 22:38, as a metaphor for the two powers ordained by God: the spiritual sword wielded by the Church, and the temporal sword wielded by kings and emperors. According to Innocent, both swords belonged to the Church, but the temporal sword was to be exercised by secular rulers on behalf of ecclesiastical authority. In this model, the pope was like the sun, radiating divine light directly, while kings were like the moon, deriving their authority indirectly from the Church. Under Innocent, the papacy exerted unprecedented control over European monarchs, intervening in royal elections, calling for Crusades, and convening the Fourth Lateran Council (1215), which codified doctrine, reformed clerical life, and asserted papal authority over all Christendom.
The Crusades, launched initially as a defensive response to the spread of Islam and the loss of Christian lands in the East, soon became a complex mixture of genuine piety, misguided zeal, and worldly ambition. Pope Urban II's call to arms at the Council of Clermont in 1095 urged Christians to reclaim Jerusalem from Muslim control, and many responded with the belief that fighting for the Holy Land would not only protect Christendom but also secure eternal salvation. Crusaders were often promised the remission of sins, and some believed that dying in battle guaranteed entrance into heaven. Alongside this theological motivation, however, the Crusades became entangled with superstition, materialism, and folly. Pilgrims and soldiers alike sought relics, engaged in dubious mystical practices, and pursued glory and wealth as much as spiritual reward. Tragic episodes such as the Children’s Crusade—in which thousands of children set out for the Holy Land and many perished or were sold into slavery—revealed the naiveté and emotional fervor that often accompanied crusading fervor. The Fourth Crusade (1204) marked a low point, when Western crusaders, instead of reaching the Holy Land, sacked the Christian city of Constantinople, permanently damaging relations between Eastern and Western Christianity. While the Crusades were initially conceived as a means of protecting Christendom, they ultimately exposed the moral contradictions of an age that blurred the line between spiritual devotion and political conquest.
This era of centralized spiritual power also witnessed growing dissent from groups who challenged the moral and theological legitimacy of the papacy. Among them were the Waldensians, followers of Peter Waldo, a wealthy merchant from Lyon who renounced his possessions in the late twelfth century to preach a life of apostolic poverty and devotion to Scripture. The Waldensians criticized the wealth and corruption of the clergy, rejected transubstantiation, and insisted that laypeople had the right to read and interpret the Bible in the vernacular. However, they affirmed many core Christian doctrines, their unauthorized preaching and rejection of papal authority led to their condemnation as heretics at the Third Lateran Council (1179). Subjected to excommunication, persecution, and military suppression, the Waldensians endured centuries of violence at the hands of both Church and State. Their survival and continued witness became a powerful symbol of resistance to the excesses of ecclesiastical power and would later influence the Protestant Reformation.
The Roman Church perpetuated pre-Christian superstitions. Superstition, prayers to the dead, and magical items like relics were all held over from paganism and should have been rejected on the basis of clear general revelation, let alone by scripture. The failure to show the culpability of pagan beliefs was linked to the failure to understand how to disciple the nations.
V. Doctrinal Deepening: Purgatory, Mary, Prayers to the Dead, Monasticism, and Celibacy
As the medieval Church matured in power and structure, so too did its doctrines deepen and expand, particularly concerning the afterlife and the spiritual hierarchy of the Christian life. Among the most influential developments of this period was the formalization of the doctrine of purgatory—a state of purification after death for those who died in grace but were not yet fully cleansed from the effects of sin. Though early Christian writers spoke of post-mortem purification, it was not until the twelfth and thirteenth centuries that purgatory became a fully defined and widely taught doctrine. Theologians like Gregory the Great and later Thomas Aquinas helped systematize the belief that souls in purgatory could be aided by the prayers of the living, the sacrifice of the Mass, and the application of indulgences. This idea reinforced the Church’s role as the mediator between God and man—not only in life, but beyond death.
During the high medieval period, devotion to Mary, the mother of Jesus, increased dramatically, both in theology and popular piety. She was exalted as the “Queen of Heaven,” the chief intercessor for sinners, and was believed to wield great influence with her Son. Doctrines such as her perpetual virginity, sinlessness, and role as mediatrix of all gracesbecame widely accepted in the Church, even if not always formally defined. Marian feast days, pilgrimages, and artistic representations flourished, and believers were encouraged to pray the Ave Maria and seek Mary’s aid in times of trial. This intense devotion reflected a desire for a compassionate figure in the heavenly court, but it also led to concerns about her being elevated beyond her biblical role. The Reformers strongly rejected these developments, insisting that Christ alone is the mediator between God and man (1 Timothy 2:5), and that Mary, though honored as the mother of the Lord, was a sinner in need of grace like all others. They affirmed the virgin birth of Christ but denied her perpetual virginity and rejected any notion of Marian intercession or veneration. In their view, the cult of Mary had become a dangerous distraction from the sufficiency of Christ and a distortion of true worship grounded in Scripture alone.
The beliefs in purgatory, praying to the dead saints, superstitious relics, and the “queen of heaven” were all important parts of Mediterranean paganism. Purgatory derives from the Egyptian Book of the Dead in ancient times. The mother goddess and goddess worship were common parts of paganism. The story of the Roman church is a story of compromising with paganism. This is due to not understanding the Biblical worldview and seeing the culpability of pagan belief. Instead, it was said that the pagan beliefs were a preparation for the Gospel, where the pagan got as close as he could without the Bible.
In parallel with these doctrinal developments, the monastic ideal rose to prominence as the highest form of Christian devotion. Inspired by the early desert fathers and formalized in the Rule of Saint Benedict, monasticism offered a structured life of prayer, labor, study, and renunciation of the world. Monks and nuns took vows of poverty, chastity, and obedience, and were viewed as spiritual athletes who pursued holiness beyond the reach of ordinary laypeople. In time, the ideal of celibacy was extended to the priesthood as well. The Gregorian Reform movement of the 11th century mandated clerical celibacy in the West, asserting that those who refrained from marriage were better suited to serve God in purity and undivided attention. Celibacy, like monasticism, was seen as a higher spiritual state—one that more closely conformed to the life of Christ and the apostolic example.
These teachings and practices helped shape a deeply hierarchical and sacramental vision of Christian life, where spiritual perfection was associated with withdrawal from the world, renunciation of bodily pleasures, and a mystical union with God through asceticism. The Church, as the steward of this system, mediated grace through sacraments, guided souls through penance and intercession, and maintained the spiritual economy of merit and satisfaction that undergirded doctrines like purgatory.
The Reformed tradition, however, rejected these developments as unbiblical and burdensome additions to the gospel of grace. Reformers like Martin Luther and John Calvin denied the existence of purgatory, arguing that it had no foundation in Scripture and undermined the sufficiency of Christ’s atonement. They taught that salvation is by grace through faith alone, and that the believer, justified by Christ’s righteousness, has no need of further purification after death. Likewise, the Reformers criticized monasticism as a distortion of the Christian calling. They opposed the idea that withdrawal from the world constituted a higher spiritual state, insisting instead that holiness was to be pursued in ordinary vocations, family life, and service to neighbor. Clerical celibacy was similarly rejected, not only because it lacked scriptural warrant, but because it imposed an unnatural burden on ministers and exalted a false ideal of spirituality. In place of monastic vows and priestly abstinence, the Reformers emphasized the priesthood of all believers and the dignity of marriage as a gift from God. The Roman Church’s insistence on celibacy was the outcome of their otherworldliness that burdened all of the Holy Roman Empire. The Reformers brought attention back to the glory of God revealed in all of his works and the dignity of work in this life.
VI. Scholasticism and Pagan Philosophy
The thirteenth century witnessed the full flowering of scholasticism, a theological and philosophical movement that sought to articulate the truths of the Christian faith through the rigorous use of reason, especially in the university setting. Its most famous representative was Thomas Aquinas (1225–1274), a Dominican friar whose work represents the high-water mark of the synthesis between Christian theology and Aristotelian philosophy. In his monumental Summa Theologiae, Aquinas attempted to show that faith and reason are not opposed but complementary: reason, when rightly used, can prepare the soul for faith and clarify its content. Yet Aquinas also maintained that we cannot know by reason alone that the world was created in time; that truth, he said, is revealed only by Scripture. Thus, for all his confidence in human reason, Aquinas said it could not show that God the Creator is real as against the Greek Unmoved Mover who is co-eternal with the material world.
The scholastic method is based on the rejection of clear general revelation of God and the moral law. This method relied heavily on pre-Christian philosophers, particularly Aristotle. Aquinas famously referred to Aristotle as “the Philosopher,” and regarded him as the greatest guide human reason could have apart from the light of the gospel. In many ways, Aristotle was to Aquinas what Scripture was to the apostles—a foundational authority. Aquinas did not think that natural theology could correct Aristotle about God–Aristotle got it right as far as general revelation goes. This admiration for pagan wisdom shaped not only theology but literature as well. In Dante’s Divine Comedy, for instance, Aristotle, Plato, and other virtuous pagans are placed in Limbo, not Hell, because, as Dante explains, they did not sin but merely lacked the knowledge of Christ. This artistic judgment reflected a broader scholastic view that reason, apart from revelation, taught the pagan system and they could not have known any better, and that philosophy (the natural) must be perfected by grace.
Yet this exaltation of pagan philosophy became, in the view of the Reformers, the ongoing sin of scholasticism. They contended that the medieval synthesis placed too much confidence in the capacities of fallen reason and blurred the distinction between the wisdom of this world and the truth of divine revelation. The Reformers rejected the notion that Aristotle—or any pagan philosopher—could serve as a trustworthy guide to theology. Scripture alone was to be the source and norm of Christian doctrine, and the use of speculative metaphysics was seen as a dangerous intrusion into the mysteries of faith. This was especially evident in the doctrine of the Eucharist, where Aristotelian categories of “substance” and “accidents” were used to explain transubstantiation—the belief that the substance of bread and wine becomes the actual body and blood of Christ, while the outward appearances remain unchanged. This doctrine was formally defined at the Fourth Lateran Council in 1215 and further affirmed by Aquinas.
The Reformed tradition flatly rejected transubstantiation as philosophically contrived and scripturally unfounded. They viewed it as a distortion of the Lord’s Supper, which Christ instituted not as a repeated sacrifice or metaphysical transformation, but as a spiritual communion with His body and blood through faith. Reformers like Calvin insisted that Christ is truly present in the Eucharist, but spiritually, not physically or materially. The bread and wine are signs and seals of God’s promise, not objects of veneration. Moreover, the Reformers saw the scholastic reliance on pagan philosophy as symptomatic of a deeper theological error: the Church had entrusted the mysteries of God to the categories of fallen man, and in doing so, had compromised the clarity and sufficiency of God’s Word. General Revelation clearly revealed that the pagan systems were without excuse in their unbelief and idolatry.
VII. Indulgences, Trent, and the Church’s Power
Of all the doctrines and practices that defined medieval Roman Catholicism, none played a more explosive role in the dawn of the Reformation than the doctrine of indulgences. Originally rooted in the Church’s understanding of penance and temporal punishment, indulgences were intended as a pastoral means of helping the faithful satisfy the earthly consequences of forgiven sin. According to medieval theology, even after guilt was absolved through confession, a soul still needed to undergo a period of temporal purification, either through acts of penance in this life or through the suffering of purgatory in the next. The Church taught that it could draw on the “treasury of merit”—the accumulated spiritual surplus of Christ and the saints—to reduce or remove this punishment, applying it to individuals through the granting of an indulgence.
At first, indulgences were connected to spiritual disciplines such as pilgrimages, prayers, or acts of charity. However, by the late Middle Ages, they increasingly became monetized, transforming a once-spiritual practice into a system of ecclesiastical finance. The construction of massive building projects, including St. Peter’s Basilica in Rome, relied heavily on the sale of indulgences to raise funds. Preachers such as Johann Tetzel famously claimed that purchasing an indulgence could release a soul from purgatory—summarized in the infamous jingle: “As soon as the coin in the coffer rings, the soul from purgatory springs.” This commodification of grace outraged many observers and confirmed, in the eyes of critics, that the Church had become more concerned with wealth and power than with true repentance and salvation.
These abuses directly led to the Protestant Reformation. In 1517, Martin Luther, a German monk and theologian, posted his Ninety-Five Theses in protest of the sale of indulgences, insisting that forgiveness could not be bought and that repentance was a matter of the heart, not of financial transaction. Luther’s challenge quickly spread across Europe, igniting a movement that would expose deeper theological disagreements about the authority of the pope, the nature of salvation, and the role of Scripture. At the heart of the controversy was a question of spiritual power: could the Church truly remit the penalties of sin for a price, or had it overstepped its divine mandate?
The concern for Martin Luther was certainty. The Bible teaches us we can be certain of our salvation. Yet, the Roman Church’s teachings tell us that we cannot. We must be absolved by a priest, and if we sin after this and die before confession, we are lost. Furthermore, our salvation relies on our works. Any sinner knows how unreliable and untrustworthy they are. To have certainty our salvation must be due to God and his assurance of salvation.
For the Reformed tradition, the doctrine of indulgences was not merely an abuse, but a symptom of a false gospel of works—one that subordinated the sufficiency of Christ’s atonement to human effort, ecclesiastical mediation, and sacramental systems. The Reformers taught that Christ alone is the source of forgiveness, and that salvation is by grace through faith, not by works, payments, or institutional authority. No human being, not even the pope, could offer release from God’s judgment apart from the promises revealed in Scripture. The Reformation thus marked a radical re-centering of Christian faith around the Word of God, the finished work of Christ, and the direct access of every believer to God through faith.
One of the most fundamental differences between Roman Catholicism and the Protestant Reformation lies in the question of authority—specifically, whether the Church is above the Bible or subject to it. By the late Middle Ages, the Catholic Church had come to teach that Sacred Scripture and Sacred Tradition, as interpreted and preserved by the Magisterium (the teaching authority of the Church), are equal sources of divine revelation. In practice, this meant that the Church claimed the right to define the meaning of Scripture, and even to determine its canon and interpretation. This idea was formalized at the Council of Trent (1546), where it was declared that the Church “does not derive her certainty about all revealed truths from the Holy Scriptures alone.” This marked a clear declaration that the Church’s authority stood alongside—and in effect, above—the Bible, since it claimed to be the sole authentic interpreter of God’s Word. The Reformers flatly rejected this view. For them, the Bible alone (sola scriptura) is the highest authority in matters of faith and practice. While they respected church councils and tradition, they insisted that all teachings must be tested by Scripture, which is the final, sufficient, and clear revelation of God’s will. The Reformers saw the Catholic elevation of Church authority above Scripture as a grave error that led to doctrinal corruption, spiritual bondage, and the loss of the gospel itself.
At the Council of Trent (1545–1563), the Roman Catholic Church issued a series of anathemas—formal condemnations—against central teachings of the Protestant Reformation, effectively drawing a clear and permanent theological line between the two traditions. Trent declared anathema on anyone who taught justification by faith alone (sola fide), insisting instead that both faith and works are necessary for salvation and that justification is a process, not a one-time declaration. The Council also anathematized those who denied the seven sacraments, upheld only two (baptism and the Lord’s Supper), or denied the sacrificial nature of the Mass. It condemned the Reformed rejection of transubstantiation, the authority of the pope, and the meritorious role of human cooperation with grace. Even the doctrine of assurance of salvation—the idea that a believer can know with confidence that he is saved—was condemned. By these declarations, the Catholic Church not only defended its medieval theology but also solidified its rejection of the gospel principles at the heart of the Reformation. The Reformers, in turn, viewed Trent as a tragic hardening of error—a Council that doubled down on human tradition, ecclesiastical authority, and works-based righteousness, rather than returning to the clear teaching of Scripture and the sufficiency of Christ.
Vatican II (1962–1965), convened under Pope John XXIII, sought to update the Church’s relationship with the modern world, leading to liturgical reforms, a more open stance toward religious liberty, and a focus on the role of the laity. While Vatican II promoted dialogue with other Christians and recognized elements of truth in other religions, it did not embrace core Protestant doctrines such as sola scriptura (Scripture alone) or sola fide (faith alone). Instead, it reaffirmed the Catholic Church as the fullness of truth and the ordinary means of salvation. However, influenced by theologians like Karl Rahner, Vatican II introduced the idea of “anonymous Christians”—the notion that non-Christians who seek truth and live according to conscience may, unknowingly, receive saving grace through Christ. While intended as a charitable expansion of the Church’s missionary outlook, this idea remains deeply problematic from a Reformed perspective, which holds that salvation comes only through explicit faith in Christ, as revealed in Scripture and received by grace.
Attempts at Ecumenical unity in the later part of the 20th century that included Reformed thinkers as esteemed as J.I. Packer and John Stott, while correctly resisted by Martyn Llyod-Jones, had to overlook that the Roman Catholics had not changed since the Reformation but had indeed “doubled down” on their doctrines. Lloyd-Jones said that unity must be based on truth and that the Reformeed Evangelical didn’t share foundational truth with either the liberals in the Chruch of England or the Roman Catholic church, and so attempts at unity were at best only sentimental. It should be noted that J.I. Packer later said Llyod-Jones was right.