Other gospel writers make much of Jesus' baptism. Luke slides it in as an afterthought. Having already told us that John had been arrested, he backtracks, mentioning in passing that Jesus had turned up one day and got himself baptised by the hairy shirted shouter, and then hurries on to Jesus' family tree.
God has just spoken, saying "You are my dearly loved son, and you bring me great joy."
That's Jesus' heavenly ancestry, but Luke also wants to show us his earthly forbears. This takes the long way round, but ends up in the same place "...the son of God."
Adam was the son of God, Jesus is the Son of God.
Humanity 2.0. That's pretty clear, isn't it? After a long and largely unsuccessful experiment, God has brought out a better model. But unlike the business way of doing things, where customers of the old version have to gnash their teeth, splash out on a new model and throw the old one into a drawer, God's plans for the Mark One version of the human race include a full upgrade.
John the Baptist made it clear: the original version of humanity is grubby and flawed. He urged people to accept a baptism of repentance for the forgiveness of their sins. But the new improved Jesus version will bring along a baptism of fire with the Holy Spirit. Sounds as though he envisaged the new operating system having a deal of pain, along with the gain.
We'll need to watch Jesus carefully, and see how straightforward the upgrade path is going to be.