John 1: 6-8, 19-28 John the Baptist spoke of the One Who was to come after him.
6There was a man sent from God, whose name was John. 7He came as a witness, to bear witness about the light, that all might believe through him. 8He was not the light, but came to bear witness about the light.
19And this is the testimony of John, when the Jews sent priests and Levites from Jerusalem to ask him, “Who are you?” 20He confessed, and did not deny, but confessed, “I am not the Christ.” 21And they asked him, “What then? Are you Elijah?” He said, “I am not.” “Are you the Prophet?” And he answered, “No.” 22So they said to him, “Who are you? We need to give an answer to those who sent us. What do you say about yourself?” 23He said, “I am the voice of one crying out in the wilderness, ‘Make straight the way of the Lord,’ as the prophet Isaiah said.”
24(Now they had been sent from the Pharisees.) 25They asked him, “Then why are you baptizing, if you are neither the Christ, nor Elijah, nor the Prophet?” 26John answered them, “I baptize with water, but among you stands one you do not know, 27even he who comes after me, the strap of whose sandal I am not worthy to untie.” 28These things took place in Bethany across the Jordan, where John was baptizing.