It was from heaven
John 1:6 There was a man sent from God, whose name was John.
Luke 7:30 But the Pharisees and lawyers rejected the counsel of God against themselves, being not baptized of him.
Nicodemus was a man of the Pharisees which is likely why Jesus first words to him when he come at night was
John 3:5 Jesus answered, Verily, verily, I say unto thee, Except a man be born of water and of the Spirit, he cannot enter into the kingdom of God.
John's baptism was from heaven
John 1:33 And I knew him not: but he that sent me to baptize with water, the same said unto me, Upon whom thou shalt see the Spirit descending, and remaining on him, the same is he which baptizeth with the Holy Ghost.
And whereas Pharisees and lawyers rejected the counsel of God against themselves not being baptized by John
These justified God by being baptized with the baptism of John
Luke 7:29 And all the people that heard him, and the publicans, justified God, being baptized with the baptism of John.
They were justifying God,
In contrast to the Pharisees (the people doing the will of God being baptized by John) he told them
Verily I say unto you, That the publicans and the harlots go into the kingdom of God before you.
Jus thought I would add this to the conversation