Matthew Henry Commentary John 1:19-28

"And this is the witness of John, when the Jews sent unto him from Jerusalem priests and Levites to ask him, Who art thou? And he confessed, and denied not; and he confessed, I am not the Christ. And they asked him, What then? Art thou Elijah? And he saith, I am not. Art thou the prophet? And he answered, No. They said therefore unto him, Who art thou? that we may give an answer to them that sent us. What sayest thou of thyself? He said, I am the voice of one crying in the wilderness, Make straight the way of the Lord, as said Isaiah the prophet. And they had been sent from the Pharisees. And they asked him, and said unto him, Why then baptizest thou, if thou art not the Christ, neither Elijah, neither the prophet? John answered them, saying, I baptize in water: in the midst of you standeth one whom ye know not, [even] he that cometh after me, the latchet of whose shoe I am not worthy to unloose. These things were done in Bethany beyond the Jordan, where John was baptizing." — John 1:19-28 (ASV)

John denies being the Christ, who was then expected and waited for. He came in the spirit and power of Elias, but he was not the person of Elias. John was not that Prophet whom Moses said the Lord would raise up for them from among their brothers, like him. He was not the kind of prophet they expected, one who would rescue them from the Romans.

The account John gave of himself was such as to stir and awaken them to listen to him. He baptized the people with water as a profession of repentance and as an outward sign of the spiritual blessings to be conferred on them by the Messiah—who was in their midst, though they did not know him, and for whom John considered himself unworthy to perform even the most humble service.