By Morgan Cates

I recently heard a story of a young man who claimed he, “converted from Southern Baptist to Catholic.” When I heard this my initial internal response was, “no, you converted from Christianity to Catholicism.” In the name of unity and peace, developments like the John 17 movement claim that Catholicism is just another Christian denomination, and regardless of doctrinal differences we are still brothers in Christ. However, this is contrary to what Christ taught His disciples, “Do you think that I have come to give peace on earth? No, I tell you, but rather division” (Luke 12:51). We should not seek out division, but neither should we cower from it. Division over primary doctrines is actually a positive thing. This is the same ideal that the reformer Martin Luther believed in when he proclaimed, “Peace if possible. Truth at all costs.” Doctrine matters, and we have a Biblical responsibility in our fight for theological truth (Titus 2:1). 


There are essentially three tiers of Christian doctrine. Third tier doctrines like Bible translation or eschatology views are doctrines that, although important, should not cause any division or rift between fellow believers. Second tier doctrines are beliefs concerning abortion, marriage, or women pastors. These are beliefs that do not necessarily point to a lack of salvation, but are important enough that they should cause a healthy division between believers. First tier doctrines, on the other hand, are closed handed issues that are not up for debate. Things like the inerrancy of Scripture, Christology, and salvific doctrine are beliefs that sit at the core of the Christian faith. First tier doctrines represent what it means to believe in Christianity. Therefore, if a person does not agree with these doctrines, it implies that they do not hold an orthodox view of the Christian faith. Protestants and Catholics have major disagreements on these highly important doctrines, which is what makes Catholicism a separate religion from Christianity. In this article we will discuss a brief overview of several of these doctrines. In 1992 Pope John Paul II, the leader of the Catholic Church from 1978 to 2005, published the Catechism of the Catholic Church where he outlined doctrines of the Catholic faith, many of which are contrary to the Christian faith. Oftentimes Catholics will claim that their beliefs are misrepresented or misunderstood by Protestants, and that Christians will make misguided assumptions about Catholic doctrine in order to perpetrate better arguments. In an effort to avoid this claim, this article will cite Pope John Paul II’s writings to be sure that Catholicism is charitably represented.  



The divide between Catholicism and Protestantism begins at the center of Christianity: the Bible. As discussed in the first TJC Young Adults article How did we get the Bible, there is a serious difference between the Catholic Bible and the Christian Bible. The Catholic Bible has 15 extra books that the Christian Bible does not include. These books are known as the Apocrypha. 

The Christian Church does not include these books in the Bible because they do not align theologically with the rest of the Old Testament. The official Catholic doctrine on these books is:


"For Holy Mother Church, relying on the faith of the apostolic age, accepts as sacred and canonical the books of the Old and the New Testaments, whole and entire, with all their parts, on the grounds that, written under the inspiration of the Holy Spirit, they have God as their author, and have been handed on as such to the Church herself” (CCC 105).


This catechism includes the Apocrypha in the Old Testament Canon (CCC 120). In return, Christian doctrine argues that these 15 books could not possibly have been written under the inspiration of the Holy Spirit, as the Catechism claims, because they contradict teachings in other inspired books. To claim something is true that is in contrast to the Word of God would be a claim to falsehood, it would be a lie. However, “it is impossible for God to lie” (Hebrews 6:18), which means it is impossible for God to contradict Himself. Therefore, these books cannot possibly be the inspired Word of God. 



Another huge divide between these two faiths is their stance on salvation, or soteriology. Catholic tradition will readily affirm justification by faith, like Christians do, but they will follow that affirmation with an additional list of things that are required in order to complete your salvation. Catholicism believes that baptism (CCC 1987), church attendance (CCC 846), penance (CCC 1422), and merits (CCC 2010) are necessary for salvation. On the contrary, Christians believe that, “by grace you have been saved through faith. And this is not your own doing; it is the gift of God” (Ephesians 2:8). The Christian faith believes that the only hope for humanity is in the atoning work of Christ which is received purely by grace alone through faith alone in Christ alone. Protestant Christians hold firmly to the belief that there is absolutely nothing that can be done to add to or warrant our salvation (Romans 5:1). It is purely a work of the Lord from beginning to end (Titus 3:5).


Confession and Intercession 

A third demarcation between these two religions is their views on confession and intercession. Catholic doctrine claims that simply by confession to another human, a man, “opens himself up again to God” (CCC 1455). This leaves confession directly to the Lord out of the equation. This distortion also leads to the doctrine that confessing sins to a priest is essential (CCC 1456). In addition to this, Catholic tradition holds to praying for dead saints like Mary and Peter to intercede on their behalf. However, the Christian Bible holds that, “there is one mediator between God and men, the man Christ Jesus” (1 Timothy 2:5), and, “there shall not be found among you anyone… who inquires of the dead” (Deuteronomy 18:10-11). Christians are called to confess their sins to each other in an effort to hold each other accountable and fight their sins together (James 5:16), but God alone can forgive our sins because our sins are committed against Him (Mark 2:7). 


There are more doctrines like pedobaptism, mortal sins versus venial sins, and purgatory that divide these two religions, but the ones outlined in this article give a broad enough view to effectively debunk the misconception that Catholicism is simply another Christian denomination. The purpose of this article is not to make the argument that a practicing Catholic cannot be a regenerate believer, but it is making the argument that if they are, it is in spite of what the Roman Catholic Church is teaching them, not because of it. John Piper describes Catholics who are truly saved as, “devout and inconsistent.” They are devout in the fact that they have truly given over themselves to Christ as their savior; they are genuine about their wholehearted faith. However, they are inconsistent in that their doctrine does not align with the authenticity of their faith.