Catechism of the Catholic Church §537 — excerpt
Through Baptism the Christian is sacramentally assimilated to Jesus, who in his own baptism anticipates his death and resurrection. the Christian must enter into this mystery of humble self-abasement and repentance, go down into the water with Jesus in order to rise with him, be…
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.
Also cites: St. Gregory of Nazianzus, Oratio 40, 9: PG 36, 369 · St. Hilary of Poitiers, In Matth. 2, 5: PL 9, 927