St Paul of Tarsus
Dates: first century
Nationality: Jewish, and a Roman citizen
Occupation: Apostle to the Gentiles.
Some would argue with the idea of St Paul being a Catholic convert, though he is indisputably one of the most famous of all converts to Christianity. His story is told in the Acts of the Apostles, and he was himself the author of many books of the New Testament.
It is not anachronistic to describe Paul as “Catholic”; the terminology of “Catholic Church” had first been used within living memory of Christ Himself. St Ignatius (probably born between 35 and 50 A.D. and possibly appointed Bishop of Antioch by St Peter) used the Greek word "Katholicos" to describe the universality of the Church established by Christ, and to draw a distinction between that Church and the early heretical dissenters. (St. Augustine, when writing about the Church some 300 years later, refers to her several hundred times as the “Catholic Church”.)
Paul famously had his disagreements with St Peter, as is clear in Galatians 2. However, it is equally clear from that chapter that Paul recognises the authority of Peter (and of James and John), accepting instruction from them (for example, in being mindful of the poor).
Catholic teaching is, of course, fully in accordance with the teaching of St Paul. In relation to the Eucharist, for example, Paul makes it quite clear that he believes in the real presence of Christ:
“Whosoever shall eat this bread, or drink the chalice of the Lord unworthily, shall be guilty of the body and of the blood of the Lord. … For anyone who eats and drinks without discerning the body eats and drinks judgement upon himself” (1 Cor 11:27-29).