"Let it be so now," Jesus says, "for it is fitting for us to fulfill all righteousness" (Matthew 3:15)
It comes as no surprise that Jesus in Matthew's Gospel wants to "fulfill all righteousness." Matthew, of all the gospels, is very interested in righteousness, that sense of a life fitting in with the will of God. I fear, however, that in interpreting the debate between John the Baptist and Jesus about who should be baptizing whom, we read it with the ears of American individualism. We can too easily hear it as an argument about Jesus' personal need for baptism, just as we so often assume that baptism is an individual act of repentance and commitment.
But Jesus clearly sees this as more than an individual act: "it is fitting for us to fulfill all righteousness." John's baptism of repentance is ultimately about the whole people of Israel needing a new start, a re-entry into the Jordan waters that marked the beginning of their life in the promised land. Jesus is affirming John's public ministry in this act, and so affirming that the kingdom of God is more than a dwelling somewhere deep in our individual souls. It is a new beginning for all, one in which Jesus as God-with-us stands at our side, dripping wet.