John’s ministry foreshadows Pentecost by stressing that only the Messiah can, by his work and his Spirit (Psalm 51:1–19), redeem from sin, and so it is Jesus for whom they are waiting (Hebrews 9:8–28).
In Matthew 3:11 John contrasts his ministry with that of the greater ministry of the Messiah, who provides what he cannot. Water alone cannot redeem from sin, since this can only be done by the Holy Spirit (Psalm 51:13). John conveys that it is not him, but Jesus whom they are awaiting (see Hebrews 9:8–28). The baptism of the Holy Spirit with Pentecost is highly significant as the Holy Spirit then came to live with the faithful in the congregation, thereby fulfilling what the baptism of John prefigured. Prior to then the faithful had only the hope of the promise, but with Pentecost this became a reality. Moreover, it is important to note that Jesus gives his Spirit to all the faithful who have been baptized, including those baptized by John1
11 Moi, je vous baptise d'eau, pour vous amener à la repentance; mais celui qui vient après moi est plus puissant que moi, et je ne suis pas digne de porter ses souliers. Lui, il vous baptisera du Saint-Esprit et de feu.