Was Saint Paul one of the twelve Apostles?

Paul was not one of the 12 Apostles selected by Jesus during His public ministry. However, he was called personally by the Lord, and the manner of his call made Paul a witness of Christ’s Resurrection – a principal criterion for being an Apostle (Acts 1:22). Pope Benedict XVI wrote that some have thus called him the “13th Apostle.”

There is an interesting parallel with events in the life of God’s people Israel. Joseph’s twelfth-share of his father Jacob’s inheritance was given by Jacob to Joseph’s two sons, Manassas and Ephraim, and on an equal basis with Joseph’s eleven brothers. Thus, the land of Canaan was divided into thirteen portions and given to eleven brothers and the two sons of the twelfth. Similarly, in the new covenant there are 13 Apostles, the Eleven plus two - Matthias (chosen by the Church), and Paul (chosen by Christ) - both called to serve in the mission field of the Church.