Pope John Paul II
Dominum et Vivificantem §19
Dominum et Vivificantem: On the Holy Spirit in the Life of the Church and the World
19 Even though in his hometown of Nazareth Jesus is not accepted as the Messiah, nonetheless, at the beginning of his public activity, his messianic mission in the Holy Spirit is revealed to the people by John the Baptist. The latter, the son of Zechariah and Elizabeth, foretells at the Jordan the coming of the Messiah and administers the baptism of repentance. He says: "I baptize you with water; he who is mightier than I is coming, the thong of whose sandals I am not worthy to untie; he will baptize you with the Holy Spirit and with fire." John the Baptist foretells the Messiah-Christ not only as the one who "is coming" in the Holy Spirit but also as the one who "brings" the Holy Spirit, as Jesus will reveal more clearly in the Upper Room. Here John faithfully echoes the words of Isaiah, words which in the ancient Prophet concerned the future, while in John's teaching on the banks of the Jordan they are the immediate introduction to the new messianic reality. John is not only a prophet but also a messenger: he is the precursor of Christ. What he foretells is accomplished before the eyes of all. Jesus of Nazareth too comes to the Jordan to receive the baptism of repentance. At the sight of him arriving, John proclaims: "Behold, the Lamb of God, who takes away the sin of the world." He says this through the inspiration of the Holy Spirit, bearing witness to the fulfillment of the prophecy of Isaiah. At the same time he confesses his faith in the redeeming mission of Jesus of Nazareth. On the lips of John the Baptist, "Lamb of God" is an expression of truth about the Redeemer no less significant than the one used by Isaiah: "Servant of the Lord." Thus, by the testimony of John at the Jordan, Jesus of Nazareth, rejected by his own fellow-citizens, is exalted before the eyes of Israel as the Messiah, that is to say the "One Anointed" with the Holy Spirit. And this testimony is corroborated by another testimony of a higher order, mentioned by the three Synoptics. For when all the people were baptized and as Jesus, having received baptism, was praying, "the heaven was opened, and the Holy Spirit descended upon him in bodily form, as a dove" and at the same time "a voice from heaven said 'This is my beloved Son, with whom I am well pleased.'" This is a Trinitarian theophany which bears witness to the exaltation of Christ on the occasion of his baptism in the Jordan. It not only confirms the testimony of John the Baptist but also reveals another more profound dimension of the truth about Jesus of Nazareth as Messiah. It is this: the Messiah is the beloved Son of the Father. His solemn exaltation cannot be reduced to the messianic mission of the "Servant of the Lord." In the light of the theophany at the Jordan, this exaltation touches the mystery of the very person of the Messiah. He has been raised up because he is the beloved Son in whom God is well pleased. The voice from on high says: "my Son."
Source: Dominum et Vivificantem (Vatican.va)