Listen to John 1, verses 29-34:
John 1:29 The next day John saw Jesus coming toward him and said, "Look, the Lamb of God, who takes away the sin of the world!
John 1:30 This is the one I meant when I said, `A man who comes after me has surpassed me because he was before me.'
John 1:31 I myself did not know him, but the reason I came baptizing with water was that he might be revealed to Israel."
John 1:32 Then John gave this testimony: "I saw the Spirit come down from heaven as a dove and remain on him.
John 1:33 I would not have known him, except that the one who sent me to baptize with water told me, `The man on whom you see the Spirit come down and remain is he who will baptize with the Holy Spirit.'
John 1:34 I have seen and I testify that this is the Son of God."