Youcat commented through CCC - Question n. 87 - Part I.

YOUCAT Question n. 87 - Part I. Why did Jesus allow John to baptize him, although he was without sin?

(Youcat answer) 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.      

A deepening through CCC

(CCC 536) The baptism of Jesus is on his part the acceptance and inauguration of his mission as God's suffering Servant. He allows himself to be numbered among sinners; he is already "the Lamb of God, who takes away the sin of the world" (Jn 1:29; cf.  Isa 53:12). Already he is anticipating the "baptism" of his bloody death (Cf. Mk 10:38;  Lk 12:50). Already he is coming to "fulfill all righteousness", that is, he is submitting himself entirely to his Father's will: out of love he consents to this baptism of death for the remission of our sins (Mt 3:15; cf.  26:39). The Father's voice responds to the Son's acceptance, proclaiming his entire delight in his Son (Cf.  Lk 3:22; Isa 42:1). The Spirit whom Jesus possessed in fullness from his conception comes to "rest on him" (Jn 1:32-33; cf.  Isa 11:2). Jesus will be the source of the Spirit for all mankind. At his baptism "the heavens were opened" (Mt 3:16) - the heavens that Adam's sin had closed - and the waters were sanctified by the descent of Jesus and the Spirit, a prelude to the new creation.     

Reflecting and meditating 

(Youcat comment) 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).

(CCC Comment)

(CCC 535) Jesus' public life begins with his baptism by John in the Jordan (Cf. Lk 3:23; Acts 1:22). John preaches "a baptism of repentance for the forgiveness of sins" (Lk 3:3). A crowd of sinners (Cf. Lk 3:10-14; Mt 3:7; 21:32) - tax collectors and soldiers, Pharisees and Sadducees, and prostitutes - come to be baptized by him. "Then Jesus appears." the Baptist hesitates, but Jesus insists and receives baptism. Then the Holy Spirit, in the form of a dove, comes upon Jesus and a voice from heaven proclaims, "This is my beloved Son" (Mt 3:13-17). This is the manifestation ("Epiphany") of Jesus as Messiah of Israel and Son of God.      

(This question: Why did Jesus allow John to baptize him, although he was without sin? is continued)