Baptism

John 3:5-6
"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. That which is born of the flesh is flesh; and that which is born of the Spirit is spirit."

Jesus Himself was baptized as an adult~

John 1:29-34 

 

The next day John seeth Jesus coming unto him, and saith, Behold the Lamb of God, which taketh away the sin of the world.

 

This is he of whom I said, After me cometh a man which is preferred before me: for he was before me.

 

And I knew him not: but that he should be made manifest to Israel, therefore am I come baptizing with water.

 

And John bare record, saying, I saw the Spirit descending from heaven like a dove, and it abode upon him.

 

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 I saw, and bare record that this is the Son of God.

In water and the Spirit~

Matthew 3:11-17
"I baptize you with  water for repentance. But after me will come one who is more powerful than I, whose sandals I am not fit to carry. He will baptize you with the Holy Spirit and with fire.

Jesus says we must be born again~

John 3:3-5

Jesus answered and said unto him, Verily, verily, I say unto thee, Except a man be born again, he cannot see the kingdom of God.