The answer is here, sort this out:
24Now they had been sent from the Pharisees.
25They asked him, and said to him, “Why then are you baptizing, if you are not the Christ, nor Elijah, nor the Prophet?”
26John answered them saying, “I baptize in water,
but among you stands One whom you do not know.
27“
It is He who comes after me, the thong of whose sandal I am not worthy to untie.”
28These things took place in Bethany beyond the Jordan, where John was baptizing.
29The next day he saw Jesus coming to him and said, “Behold, the Lamb of God who takes away the sin of the world!
30“This is He on behalf of whom I said, ‘After me comes a Man who has a higher rank than I, for He existed before me.’
31“I did not recognize Him, but so that He might be manifested to Israel, I came baptizing in water.”
32John testified saying, “I have seen the Spirit descending as a dove out of heaven, and He remained upon Him.
33“I did not recognize Him, but He who sent me to baptize in water said to me, ‘He upon whom you see the Spirit descending and remaining upon Him, this is the One who baptizes in the Holy Spirit.’
34“I myself have seen, and have testified that this is the Son of God.”