The Jordan event marks the beginning of Jesus' public mission and of his revelation as the Messiah, the Son of God. John preached "a baptism of repentance for the forgiveness of sins" (Luke 3:3). We find Jesus among the crowd of sinners coming to be baptized by John. He recognizes him and proclaims him the innocent lamb who takes away the sin of the world, to lead humanity back to communion with God. The Father expresses his pleasure with his beloved Son, who becomes an obedient servant unto death, and gives him the Spirit's power so that he can carry out his mission as the Messiah-Savior.
Jesus has certainly possessed the Spirit since his conception, but in baptism he receives a new outpouring of the Spirit, an anointing of the Holy Spirit, as St Peter attests in his speech at Cornelius' house: "God anointed Jesus of Nazareth with the Holy Spirit and with power" (Acts 10:38). This anointing is an elevation of Jesus "in the eyes of Israel as Messiah, that is to say, the 'One Anointed' with the Spirit"; it is a true exaltation of Jesus as Christ and Savior.
After his baptism in the Jordan, Jesus begins to exercise his threefold mission: a royal mission, which involves him in fighting the spirit of evil; a prophetic mission, which makes him the tireless preacher of the Good News; and a priestly mission, which spurs him to praise the Father and to offer himself to him for our salvation.
Immediately after his baptism, Jesus is "led" by the Holy Spirit into the wilderness "to be tempted by the devil". Satan suggests a triumphal Messianism to him, consisting in such spectacular wonders as turning stones into bread, throwing himself down from the pinnacle of the temple without suffering injury, achieving instantaneous political control over all the kingdoms of the world. But Jesus' choice, in total obedience to the Father's will, is clear and unequivocal: he accepts being the suffering, crucified Messiah who will give his life for the world's salvation.
Jesus' struggle with Satan, which began in the wilderness, continues throughout his life. One of his typical activities is precisely that of exorcist, which is why the crowds cry out in amazement: "With authority he commands even the unclean spirits, and they obey him" (Mk 1:27). Anyone who dares to say that Jesus' power derives from Satan is blaspheming against the Holy Spirit (Mk 3:22-30): it is in fact "by the Spirit of God" that Jesus casts out demons (Mt 12:28). As St Basil of Caesarea states, with Jesus "the devil lost his power in the presence of the Holy Spirit".
Enlivened by the power of the Spirit, what Jesus says truly expresses his mystery as the Word made flesh (Jn 1:14). It is therefore the word of someone with "authority", unlike the scribes (Mk 1:22). It is "a new teaching", as those who hear his first address in Capernaum are amazed to recognize (Mk 1:27). These are words that fulfill and surpass the Mosaic law, as becomes apparent in the Sermon on the Mount. (Mt 5:7). They are words that extend divine forgiveness to sinners, offer healing and salvation to the sick and even bring the dead back to life. They are the words of the One who was "sent by God", in whom the Spirit dwells in such a way that he can give that Spirit "without measure" (Jn 3:34).
Thus the Sprit is present in Jesus' most intimate experience, that of his divine sonship, which prompts him to call God "Abba" (Mk 14:36) with a unique trust that is not evidenced in the way any other Jew addressed the Most High. Precisely through the gift of the Spirit, Jesus will enable believers to share in his filial communion and intimacy with the Father. As St Paul assures us, it is the Holy Spirit who makes us cry out to God: "Abba, Father!" (Rom 8:15).
This filial life is the great gift we receive in Baptism. We must rediscover and constantly nurture it, making ourselves docile to the work that the Holy Spirit accomplishes in us.