To baptize means to immerse. In his baptism, Jesus descended into the sinful history of all mankind. By doing so he established a sign. In order to redeem us from our sins, he would one day be submerged in death but, through his Father’s power, reawakened to life. [535-537, 565]
Sinners – soldiers, prostitutes, tax collectors-went out to the prophet John the Baptist because they were looking for the “baptism of repentance for the forgiveness of sins” (Lk 3:3). Strictly speaking, Jesus did not need this baptism, because he was sinless. The fact that he submitted to this baptism shows us two things: Jesus takes our sins upon himself. Jesus understands his baptism as an anticipation of his Passion and Resurrection. At this sign of his willingness to die for us, the heavens open: “You are my beloved Son” (Lk 3:22b).