The Patristic Period: Part Two
"Hippolytus (c. 170-235) was the bishop of Rome in the third century and composed an important manual of church order titled On the Apostolic Tradition," in which he presents a peculiar formula for the catechesis and baptism of new converts. Following an examination period of three years and a time of fasting and prayer, the new Christians were immersed in the waters of baptism threefold, once for each person of the Trinity, while simultaneously replying that they believe in each person.