What Is Roman Catholicism?
Roman Catholicism is the largest branch of Christianity, with approximately 1.3 billion members worldwide, making up nearly 17 percent of the global population. It represents a Christian tradition that recognizes the pope as the bishop of Rome and the chief shepherd of the church, understood as Christ’s representative on earth. Its history, theology, and practices have profoundly shaped Western Christianity and continue to influence global Christianity today.
To understand Roman Catholicism, however, it is important to distinguish between the early catholic church—meaning the universal church of the first centuries—and the Roman Catholic Church as it developed during the medieval period. The latter reflects significant theological and ecclesiastical developments that moved beyond the patterns of the early church.
1. Early Catholicism: The Universal Church
The word catholic simply means “universal.” In the earliest centuries, the church understood itself as the one, holy, catholic, and apostolic community founded by Christ and His apostles. This catholic church was defined by shared confession, common worship, apostolic teaching, and unity across local congregations. Authority was vested in bishops, presbyters, and deacons who sought to maintain fidelity to apostolic tradition.
This early catholicism did not mean uniformity under one bishop of Rome, nor did it involve many of the distinctive doctrines and practices that later defined Roman Catholicism. Instead, it described the whole church spread throughout the world as united in Christ.
2. The Rise of Roman Catholicism
By the medieval period, the bishop of Rome gained increasing authority, eventually being recognized as the pope with universal jurisdiction. This marked the shift from early catholicism to Roman Catholicism. Over time, distinctive theological and institutional developments took shape:
The papacy claimed supremacy and later infallibility.
Tradition was elevated alongside Scripture as an equal source of revelation.
The seven sacraments were standardized as necessary channels of grace.
Doctrines such as purgatory, indulgences, and transubstantiation were defined.
By the time of the Reformation in the 16th century, Roman Catholicism was a highly developed system of theology, worship, and governance distinct from both Eastern Orthodoxy (separated in 1054) and emerging Protestant churches.
3. The Nature of the Catholic Church Today
Roman Catholicism today consists of twenty-four self-governing churches across six liturgical rites, with the Latin or Roman Church being the largest. All remain in communion with the pope as their chief pastor. Roman Catholic spirituality emphasizes:
Liturgical worship, centered on the Mass.
Tradition and magisterium, the teaching authority of the pope and councils.
The seven sacraments, including baptism, confirmation, Eucharist, penance, marriage, holy orders, and anointing of the sick.
Dogma and catechesis, developed over centuries through councils and papal teaching.
Roman Catholicism has historically been most influential in Europe and the Americas but today finds its greatest growth in Latin America and sub-Saharan Africa.
4. Differences from Protestantism
The Protestant Reformation (16th century) marked the great division between Catholicism and Protestantism. Some of the key points of contrast include:
Revelation: Catholicism affirms both Scripture and Tradition as authoritative; Protestantism affirms Scripture alone.
Justification: Catholicism views justification as a process involving both forgiveness and transformation; Protestantism emphasizes justification as a declarative act of God received by faith alone.
Grace: Catholicism teaches grace as infused through the sacraments; Protestantism teaches grace as imputed through faith.
Church authority: Catholicism locates ultimate authority in the pope and magisterium; Protestantism in the Word of God.
Protestants specifically rejected certain medieval Catholic practices, including indulgences, the dogma of purgatory, mandatory clerical celibacy, restricting Scripture to Latin, and papal supremacy.
While Protestantism insists on continuous reform according to Scripture, Catholicism enshrined its distinctive teachings as infallible, closing the door to reform in these areas.
5. Shared Christian Ground
Despite differences, Roman Catholicism and Protestantism share much in common. Both affirm:
One God in Trinity.
The authority of Holy Scripture.
The centrality of Christ’s death and resurrection.
The Apostles’ Creed as a summary of the faith.
As church historian Philip Schaff put it, what unites Catholics and Protestants in Christ is ultimately “far deeper, stronger and more important than what divides them.”
Conclusion
Roman Catholicism represents the largest expression of Christianity in the world. While it differs significantly from both the early catholic church and Protestant Christianity in doctrine and practice, it still confesses Christ, claims apostolic continuity, and seeks to be the universal church. Understanding its development helps clarify not only its unique identity but also its ongoing relationship to the broader Christian family.
