The Church
Matthew 16:18–19 — Christ builds His Church and gives Peter the keys of the kingdom.
Matthew 18:15–18 — disputes can be brought to “the church,” whose judgments carry authority.
1 Timothy 3:15 — the Church is called the pillar and foundation of truth.
Authority and tradition
2 Thessalonians 2:15 — believers are told to hold fast to traditions delivered both orally and in writing.
Acts 15 — a doctrinal controversy is settled by apostles and elders in council, and the decision is delivered to the churches.
Baptism
Read John 3:5, Acts 2:38, Acts 22:16, Romans 6:3–4, Titus 3:5, and 1 Peter 3:21 together before deciding what the New Testament means by baptism.
The Eucharist
Read John 6:22–71 alongside the Last Supper accounts and 1 Corinthians 10–11. Pay special attention to Paul’s warnings about profaning the body and blood of the Lord.
Faith, obedience, and works
Read Romans, Galatians, James 2, Matthew 25, Philippians 2:12–13, and the judgment passages without forcing one author to cancel another. Catholic theology insists that salvation is entirely by grace while also taking seriously Scripture’s language about obedience, perseverance, and works done in grace.