On that basis, let's imagine ourselves back to the Jordan, as Jesus himself submits to baptism. We are united to him, so let us imagine ourselves in his place. He goes down into the water, just as we did in our own baptism, and then as he comes up two things happen. There is a visible descent of the Spirit from heaven, and there is the voice of the Father which declares Jesus to be the beloved Son of God. This is what happened to Jesus, and I don't think it's a stretch to say that as we are united to Jesus this is also what happened to us. My baptism means the receipt of the promised Spirit, and the assurance of adoption by God the Father as a son.
But of course, Jesus' baptism was the beginning of the way to the cross, and contained virtually and symbolically his death and resurrection. As he went down into the waters, so he went down into the grave. As he was lifted up out of the waters, so he was raised again from death. And again, we are united with him in this death and resurrection. But isn't it striking that according to Scripture there was a sense in which Christ did not receive the Spirit until after his resurrection? Isn't it intriguing that it is primarily in his resurrection that he is declared to be the Son of God? Because, of course, the cross was his real baptism.
My baptism, his baptism, his Baptism. Sonship and the Spirit.