How do Roman Catholicism, Eastern Orthodoxy, and Protestantism differ?

Roman Catholicism, Eastern Orthodoxy, and Protestantism share a core belief in Jesus Christ and the Bible, yet they differ significantly in authority, structure, and doctrine.1

Authority and Structure

• Roman Catholicism: Centered on the papacy, the pope is the visible head of the church, holding supreme authority derived from St. Peter.12
• Eastern Orthodoxy: Composed of autonomous national churches. The ecumenical patriarch is considered "first among equals" but lacks the universal jurisdiction claimed by the pope.3
• Protestantism: Generally emphasizes the authority of Scripture alone (sola scriptura) and often rejects the necessity of a centralized, hierarchical papal authority.4

Key Doctrinal Differences

• Sacraments: Roman Catholicism and Eastern Orthodoxy both emphasize the centrality of the seven sacraments, whereas Protestant traditions vary widely in their number and interpretation.1
• Theology: A major historical point of contention between East and West is the Filioque clause regarding the procession of the Holy Spirit. Additionally, Roman Catholicism has distinct dogmas like papal infallibility and the Assumption of the Virgin Mary.31
• Justification: The Protestant Reformation introduced the doctrine of justification by faith alone, which challenged the Roman Catholic emphasis on the necessity of works alongside faith.4

While these traditions maintain different practices—such as the Eastern Orthodox use of leavened bread and the marriage of clergy before ordination—they remain united by a shared history and fundamental Christian tenets.135