The action of ritually cleansing something with water, the very action performed in Baptism, is an ancient practice.
We see it in many traditions and religions, in various forms.
In ancient Judaism, there was a ritual bath that was required at certain points in a person’s life.
It took place in a Mikveh, a special bathtub used only for this purpose, deep enough for a person to walk into and completely immerse themselves, with stairs leading into it, and stairs leading out of it. The stairs were separate, because one entered the bath unclean, and left clean.
It was out of this tradition, that John the Baptist began to baptize people in the Jordan river.
It was a baptism of repentance, a ritual indication that they were leaving their life of sin to follow God more closely.
A wonderful thing, but the one thing Jesus didn’t need.
The point of Jesus being baptized by John, wasn’t the baptism, but the progression.
Jesus taking over were John left off.
Jesus going were John couldn’t.
Jesus taking us, were no mere human could lead.
He makes baptism into something else, a cleansing by fire and the Holy Spirit.
All sin is burned away, even original sin.
Something no human being could do.
And God himself shows the result of this new baptism.
“You are my beloved Son, in whom I am well pleased.”
In our baptism, we joined the family of God, we became the younger siblings of Jesus, the children of the Father, new creations of the Spirit.
And at the end of mass, when I say “Go forth, the mass is ended” it is our command to go out into the world, and grow our family.
To bring in others to be baptized, the be born anew, of water and the Spirit, and fire.
To make all of humanity, into God’s family. Amen.