Jesus comes as a sinner to save sinners
Why does Jesus need to be baptized? After all, John's baptism (which is not the same as Christian baptism) is a baptism for sinners. Even John recognizes how strange Jesus' baptism is. He protests, “I need to be baptized by you, Jesus, not the other way around.” It's almost as if he says, “hey, I'm the sinner, not you!”
But Jesus comes
as
a sinner to
save
sinners. He steps down into the Jordan just like all the other offenders because he comes to take our place as an offender. This is the mission that His Father gave Him. If there's any question about that, just look and listen. The Spirit comes down on Him like a dove, and the Father speaks from heaven, voicing his approval. "This is my beloved Son, with whom I am well pleased." So the Father makes clear on
who
this Jesus is and
what
He is here to do. He
is
God's beloved Son. And everything He
does
is precisely what the Father has asked of Him, … including the cross.