22 So they said to him, "Who are you? We need to give an answer to those who sent us. What do you say about yourself?" 23 He said, "I am the voice of one crying out in the wilderness, 'Make straight[1] the way of the Lord,' as the prophet Isaiah said." 24 (Now they had been sent from the Pharisees.) 25 They asked him, "Then why are you baptizing, if you are neither the Christ, nor Elijah, nor the Prophet?" 26 John answered them, "I baptize with water, but among you stands one you do not know, 27 even he who comes after me, the strap of whose sandal I am not worthy to untie." 28 These things took place in Bethany across the Jordan, where John was baptizing.
29 The next day he saw Jesus coming toward him, and said, "Behold, the Lamb of God, who takes away the sin of the world! 30 This is he of whom I said, 'After me comes a man who ranks before me, because he was before me.' 31 I myself did not know him, but for this purpose I came baptizing with water, that he might be revealed to Israel."
Matthew Henry's Commentary on John 1:22-31
Commentary on John 1:19-28
(Read John 1:19-28)
John disowns himself to be the Christ, who was now 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 to them of their brethren, like unto him. He was not such a prophet as they expected, who would rescue them from the Romans. He gave such an account of himself, as might excite and awaken them to hearken 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 the midst of them, though they knew him not, and to whom he was unworthy to render the meanest service.
Commentary on John 1:29-36
(Read John 1:29-36)
John saw Jesus coming to him, and pointed him out as the Lamb of God. The paschal lamb, in the shedding and sprinkling of its blood, the roasting and eating of its flesh, and all the other circumstances of the ordinance, represented the salvation of sinners by faith in Christ. And the lambs sacrificed every morning and evening, can only refer to Christ slain as a sacrifice to redeem us to God by his blood. John came as a preacher of repentance, yet he told his followers that they were to look for the pardon of their sins to Jesus only, and to his death. It agrees with God's glory to pardon all who depend on the atoning sacrifice of Christ. He takes away the sin of the world; purchases pardon for all that repent and believe the gospel. This encourages our faith; if Christ takes away the sin of the world, then why not my sin? He bore sin for us, and so bears it from us. God could have taken away sin, by taking away the sinner, as he took away the sin of the old world; but here is a way of doing away sin, yet sparing the sinner, by making his Son sin, that is, a sin-offering, for us. See Jesus taking away sin, and let that cause hatred of sin, and resolutions against it. Let us not hold that fast, which the Lamb of God came to take away. To confirm his testimony concerning Christ, John declares the appearance at his baptism, in which God himself bore witness to him. He saw and bare record that he is the Son of God. This is the end and object of John's testimony, that Jesus was the promised Messiah. John took every opportunity that offered to lead people to Christ.