“Just as a man cannot live in the flesh unless he is born in the flesh, even so a man cannot have the spiritual life of grace unless he is born again spiritually. This regeneration is effected by Baptism: ‘Unless a man is born again of water and the Holy Spirit, he cannot enter into the kingdom of God.’” (St. Thomas Aquinas, Doctor of the Church; cf. John 3:5)
The Memorial of St. Thomas Aquinas, Priest and Doctor of the Church (1225 – 1274) is January 28.