To this point in my theological life, I have not given much thought to the significance of the baptism of Jesus. To be sure, this is not entirely my own fault. Growing up, the only significance I can recall being attached to this event was that Jesus was baptized to fulfill Old Testament prophesy predicting the coming of the Messiah.
I still think that there is Old Testament prophecy about the person of the Messiah, but I’ve grown more uncertain that it is specifically predictive. I’m more convinced that this sort of prophesy is rather interpreted by the New Testament as to be about Jesus – a move which, as a Christian, I find every reason to support.
But back to the baptism of Jesus: Barth says that the baptism of Jesus is “the prologue which opens and characterizes the whole of Jesus’ history, setting it in motion herefrom both with a definite direction and towards a specific goal. The baptism of Jesus, as His baptism, is in a sense the point of intersection of the divine change and the human decision. In the main character in this event, who here enters upon His way, who, one might almost say, stands here at the beginning of his Christian life, the two aspects, though plainly distinct, are directly one and the same.” (53)
In some other author I might worry about adoptionism a little here -but Barth hardly can be termed that from the rest of his comments even in only IV/1.
So aside from being the formal beginning of Jesus’ vocation, what actually happened in Jesus’ baptism in the Jordan? “The baptism is 1) an act in which Jesus freely, concretely, unequivocally, and unconditionally subjected and delivered Himself to, and placed Himself under the control of, the lordship of God. In the same act 2) He no less freely, concretely and unequivocally set himself in the sequence and fellowship of men who had fallen victim to the judgment of God and were referred only to His free remission of their sins. In this act in its twofold sense 3) He undertook to do in the service of God and men that which as God’s work He alone could do for men. (54)
So in baptism, Jesus submits himself to the Lordship of the father, places himself in the history and in fellowship of humanity, and thus undertook to do God’s work as he alone could do for people.