As forerunner of the Messiah John the Baptist was the last of the Old Testament prophets (11:13). And Jesus said that "among those born of women no one has arisen greater than John the Baptist." But he added that "the least in the kingdom of heaven is greater than he" (11:11). Prophetic preaching announces the good and bad consequences (wrath) of various kinds of behavior (as in 3:10). But as Matthew proceeds he will highlight the fact that the good news of belonging to the Messianic kingdom is a very different and in one sense far more important privilege.
3:1-3 John's function is to call people to repent (the Hebrew word was shubh which means to turn and change direction) because the Messiah's kingdom is about to become visible in the life and preaching of Jesus. To illustrate this he refers to a messenger who announced the imminent return of the Jewish people to Jerusalem after the exile, but Isaiah's words also pointed forward to the Messiah (Isaiah 40:1-3; compare 40:10-11).
3:4-6 The clothing and lifestyle of John the Baptist was a reminder of the severity of Elijah and other prophets (11:16-19). For the difference between John's baptism and Jesus' baptism see the next section.
3:7-9 John the Baptist makes clear that Pharisee and Sadducee teaching had been a recipe for disaster and a radical change of direction was needed to welcome the Messiah. They had assumed that by circumcision they were the rightful children of Abraham, but in God's mind the children of Abraham were those who had the same kind of faith as Abraham (John 8:33-42; as explained in Romans 4:12).
3:10 Here the tree is the Jewish religious establishment, which is about to be axed after a three year siege by the Romans Legions in AD 70 (21:41; 22:7; 23:36; 24:2, 9).
Both John and Jesus used baptism to enrol their disciples for teaching (as in John 4:1; Acts 2:41-42) But the content of their teaching after baptism was quite different. Prophets announce the bad consequences of our behaviour and what God is about to do about it, but the good news of the Messiah is that God loves us and the Holy Spirit can transform us for the perfect love of heaven.
3:11 In the Messiah's kingdom lives would be changed by the power of the Spirit (3:11). The Greek text says "He will baptize you in [or into] the Holy Spirit." The translation "baptism with the Holy Spirit" gives a wrong impression of a once for all inrush or outpouring, which misses the idea that the Messiah baptizes into the continuing life, teaching, fruit-bearing, and gifting of the Spirit (as in John 14:26; 16:13; Romans 8:11-16; 1 Corinthians 12:3-13).
This is why those who had been baptized by John the Baptist to prepare for the Messiah needed to be rebaptized as disciples of the Christ (as in Acts 19:1-6). The Galatians who had been baptized into the life and freedom of the Spirit, and had reverted to living in the flesh, needed to come back to that total dependence on the Spirit (Galatians 3:2-6; 5:1). Similarly the Romans needed to set their minds on "the things of the Spirit" and be continually transformed by the renewing of their minds (Romans 8:5; 12:2).
Several of Jesus' disciples had been baptized as disciples of John the Baptist before being baptized into Jesus school of disciples (John 1:35-37; 4:1). Since the enrolment is with a view to being taught after baptism the new disciples obviously knew very little, and the parable of the Sower (13:1-23) explains various responses that can occur among the baptized. As in the case of Peter, grasping what the teaching is about and who the Messiah really is will take time (16:13-17).
3:12 Prophets can announce the bad consequences of our behaviour (wrath), but it is the Messiah who personally divides the wheat from the tares (13:24-30). In the previous verse the fire may refer to the fire of the Spirit on the Day of Pentecost, but here it seems to refer to the gathering of the new kingdom and the imminent wrath consequences on the Jewish religious establishment (For burning with fire as a wrath consequence of being trashed on the Gehenna garbage see the comment on 13:42).
If baptism is to enrol disciples to learn with a teacher, we wonder why Jesus needed to be baptized by John the Baptist? Jesus' answer is "Let it be so now; for it is proper for us to learn in this way" (3:15). Having emptied himself to become fully man (Philippians 2:7) Jesus had to learn human language and basic reading skills in the same way as other children (Luke 2:51-52; Hebrews 2:17). And that included learning from rabbis and prophets. But when Jesus' baptism took place both the Holy Spirit and the Father made it clear that this disciple of John was the Son of God. And this may be another reason why Matthew will end his Gospel with baptism to begin learning from all three Persons of the Trinity (28:19).
3:13-15 When Jesus came for baptism John the Baptist already knew that he was the Lord (3:3), and he would soon be baptizing into the Holy Spirit's fullness and teaching (3:11). John's Gospel tells us that John the Baptist also knew that the Messiah was "The Lamb of God who keeps taking away the sin of the world" (literal translation of John 1:29, which could suggest that the cross which was still three years in the future was a visible expression in our space and time of the eternal Lambness of the Son of God). So naturally John the Baptist wonders why Jesus needed to come and learn from him. For Jesus' answer see the introduction to this section.
3:16 By way of comment on the descent of the dove, here is a quote from the conclusion to a companion book (Romans: Paul and the Power of the Spirit):
"People who are touched by the Spirit in a powerful new way might find themselves knocked to the ground like Paul, speaking in tongues, or seeing tongues of fire, as on the Day of Pentecost. Some have found themselves laughing, crying, clapping, hugging, dancing with joy, shaking like Shakers, quaking like Quakers, roaring like a young lion, or even like Jesus or Saint Francis have a dove come fluttering down upon their head.But things go badly wrong when we imagine we need to repeat the same experience again and again to maintain our spirituality. And zealous Christian workers must avoid inducing one or other of these manifestations by the energy of the flesh. Only the Holy Spirit has the right to choose a gentle breeze, breath, voice, touch, dream, nightmare, hurricane, earthquake, bright light, burning bush, or forest fire, just exactly as needed for the occasion."
In Jesus' baptism a dove fluttering down on his head as a sign of the Spirit was an appropriate reminder of the dove in the waters of the flood (Genesis 8:8-12).
3:17 At Jesus' baptism there is also a voice from heaven announcing that the Messiah is in fact the Son of God. And this will be an important theme throughout the Gospel (4:3; 14:33; 17:5; 21:37-38; 22:2; 26:63; 27:40, 43, 54). The baptism of Jesus therefore pictures the Trinitarian relationship, and it will be an essential part of Christian baptism "in the name of the Father and of the Son and of the Holy Spirit" (with which Matthew ends the Gospel).