Why Then? -John 1:24-28

John 1:24-28 ESV
Now the Pharisees who had been sent 25 questioned him, “Why then do you baptize if you are not the Messiah, nor Elijah, nor the Prophet?”
26 “I baptize with water,” John replied, “but among you stands one you do not know. 27 He is the one who comes after me, the straps of whose sandals I am not worthy to untie.”
28 This all happened at Bethany on the other side of the Jordan, where John was baptizing.

Why did John baptize? His mission was getting the people ready for the one to come. Baptism was an act of repentance, signifying a turning and leaving behind the old life, and a readiness for the salvation of God. In Acts we see instances of baptism taking place before and after the baptism of the Holy Spirit. It is Jesus Who baptizes with the Holy Spirit, Who sends the comforter and provides the living water which washes the heart clean. John's baptism is like circumcision. It is an outward sign of an inward reality. It is the circumcision of the heart and the seal of the Holy Spirit that counts. That seal and circumcision only come through the grace of Jesus. When we repent and accept Christ, we then rest in His love and grace. Jesus said at the beginning of His ministry, "Repent and believe!"

This differs from the ceremonial washing performed by the Jews. This was the sign of a new covenant that was inclusive of all that would accept His name.

Mark 1:4-8
And so John the Baptist appeared in the wilderness, preaching a baptism of repentance for the forgiveness of sins. 5 The whole Judean countryside and all the people of Jerusalem went out to him. Confessing their sins, they were baptized by him in the Jordan River. 6 John wore clothing made of camel’s hair, with a leather belt around his waist, and he ate locusts and wild honey. 7 And this was his message: “After me comes the one more powerful than I, the straps of whose sandals I am not worthy to stoop down and untie.
8 I baptize you with water, but he will baptize you with the Holy Spirit.”