Fifteen months ago today — at the Easter Vigil on April 7, 2007 — I was formally received into full communion with the Catholic Church. In honor of this milestone, here are some scripture passages that helped me on my journey from Protestantism to Catholicism:

15 Bible Verses Every Catholic Should Know

1. 2 Thess 2:15 - We are told to hold to the traditions, whether taught by word of mouth or by letter. This goes against the Protestant ideas of sola scriptura (scripture alone as the final authority) and that all forms of tradition are bad (Christ only condemned certain traditions of men in Mt 15:3 and Mk 7:9, not all types of tradition).
2. James 2:24 - We are justified by works and not by faith alone. This opposes the Protestant idea of justification by faith alone, or sola fide.
3. Phil 2:12 - We are to work out our salvation with fear and trembling; instead of simply having faith alone (sola fide), we are to be active participants, cooperating with God’s grace in our salvation.
4. 2 Peter 3:15-16 - Scripture is not clear or easily understood, and it can easily be twisted to support false doctrine. We are told that Paul’s letters contain things that are hard to understand, which contradicts the Protestant concept of the perspicuity (clearness) of scripture.
5. Rom 11:22 - We must continue in God’s kindness or we will be cut off (i.e., we can lose our salvation). This verse goes against the teaching of some Protestants, such as Calvinists, who say that believers cannot lose their salvation. (Note that other Protestants, like Wesleyans and Arminians, agree with Catholics that a believer can lose their salvation.)
6. John 3:5 - We must be born of water and the Spirit to enter the kingdom of God. Being born of water means baptism: a point reinforced in John 3:22 when the Jesus and the apostles begin baptizing.
7. 1 Pet 3:21 - baptism…now saves you (baptism is regenerative, not merely a symbol)
8. Col 1:24 - A believer’s sufferings are in some way combined with Christ’s afflictions (”complete what is lacking”) and can be applied to benefit other believers (i.e., “for your sake” and “for the sake of…the church”).
9. Rev 12:1 - Mary is depicted in heaven bodily (supporting the bodily assumption of Mary) and wearing a crown (supporting the idea that Mary is queen of heaven). (That this woman is Mary is clear from Rev 12:5…she gives birth to the Messiah.)
10. Rev 12:17 - Mary is the mother of all believers
11. 1 Cor 4:15 - Paul tells his readers, “I became your father in Christ through the gospel.” This supports the practice of Catholics calling their priests “Father”. (Protestants sometimes use Matt 23:9 to claim that calling a priest Father goes against Christ’s teachings.)
12. Acts 1:20, 25-26 - Apostolic succession; Matthias takes Judas’ apostolic ministry (”bishoprick” in the KJV).
13. 2 Tim 2:2 - Apostolic succession: Christ’s teachings were given to Paul, who taught Timothy, who is to teach faithful men, who then are to teach others.
14. John 6:53-56 - The real presence of Christ in the Eucharist (see the entire Bread of Life discourse in Jn 6:35-71).
15. 1 Cor 11:27-29 - Concomitance: the body and blood are present in both the bread and the cup. If you eat the bread or drink the cup unworthily, you sin against both the body and the blood of Christ.