John 1:25-27

25 And they asked him and said, Why then do you baptize, if you are not the Christ, nor Elijah, nor that Prophet?

26 John answered them, saying, I baptize with water, but One stands among you whom you do not know.

27 He it is who, coming after me, who has been before me; of whom I am not worthy to loosen the thong of His sandal.