In Jesus's Baptism we see Jesus doing something unnecessary and in a sense unfair.  He takes on the role of a sinner, allowing John to baptize him with his baptism of repentance for the forgiveness of sins.  At the beginning of his public life, this event foreshadows our redemption at the end of Jesus's life--his death on the cross.  Jesus loves us by lowering himself, forgetful of his status and his rights, giving himself in a way that is beyond all necessity and human logic.  Christian life is an invitation to do the same.