The distinctions between Roman Catholicism and Protestant Christianity are not secondary differences between two Christian denominations. They are two different religions divided who stand at odds regarding the very gospel itself. Is salvation finished or ongoing? Is righteousness imputed or earned? Is Christ enough or supplemented? These are the essential questions that must answered by Scripture. Truth always transcends tradition. 

Roman Catholics and Protestants share a decent number of similarities on the surface. Several include the worship of Jesus Christ, belief in the Trinity (the Father, Son, and Holy Spirit), interaction with the Bible, the concept of baptism, preaching, the need to serve others, the importance of the church, and both tend to be conservative politically. 

There are so many surface level similarities that people often make the mistake of thinking Roman Catholics and Protestants are just two slightly different denominations within Christianity itself. But that could not be further from the truth. At their core, Roman Catholicism and Protestant Christianity are two different religions. 

These differences between the two are not minor, but rather, they strike at the heart of the Christian gospel. To help you discern these key differences, I wanted to lay out several for you. 

1. Authority: Scripture Alone vs. Scripture + Tradition

• Roman Catholic View: Scripture is not the sole authority. It is interpreted through Sacred Tradition and the teaching authority of the Church (the Magisterium).

“Sacred Tradition and Sacred Scripture, then, are bound closely together, and communicate one with the other. For both of them, flowing out from the same divine well-spring, come together in some fashion to form one thing, and move towards the same goal.” — Catechism of the Catholic Church (CCC 80)

“The task of giving an authentic interpretation of the Word of God, whether in its written form or in the form of Tradition, has been entrusted to the living teaching office of the Church alone. Its authority in this matter is exercised in the name of Jesus Christ.” — CCC 85

• Protestant View (Sola Scriptura): Scripture alone is the final authority.

“All Scripture is inspired by God…” (2 Timothy 3:16–17, NASB95)

Key Distinction: Catholicism places the Church over Scripture; Protestantism submits the Church to Scripture.

2. Justification: Faith Alone vs. Faith + Works

• Roman Catholic View: Justification is a process involving faith, works, and participation in the sacraments.

“Justification is conferred in Baptism, the sacrament of faith. It conforms us to the righteousness of God, who makes us inwardly just by the power of his mercy. Its purpose is the glory of God and of Christ, and the gift of eternal life.” — CCC 1992

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