Catechism of the Catholic Church
Baptism of Jesus
In spirit let us return to the banks of the Jordan where John the Baptist administered a Baptism of repentance, exhorting to conversion. Coming up to the Precursor is Jesus, and with his presence he transformed that gesture of repentance into a solemn manifestation of his divinity. A voice suddenly comes from heaven: "You are my beloved Son; in you I am well pleased" (Mk 1, 11) and, in the form of a dove, the Spirit descends upon Jesus.
In that extraordinary event, John saw realized what had been said about the Messiah born in Bethlehem, adored by the shepherds and the Magi. He was the very One foretold by the prophets, the beloved Son of the Father; we must seek him while he can be found and call upon him while he is at hand.