The next day John 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 is preferred before me, for He was before me.’ 31 I did not know Him; but that He should be revealed to Israel, therefore I came baptizing with water.”
32 And John bore witness, saying, “I saw the Spirit descending from heaven like a dove, and He remained upon Him. 33 I did not know Him, but He who sent me to baptize with water said to me, ‘Upon whom you see the Spirit descending, and remaining on Him, this is He who baptizes with the Holy Spirit.’ 34 And I have seen and testified that this is the Son of God.” – John 1:29-34.
“Behold, the Lamb of God” (v.29). — Compare v. 36. Whether “the Lamb” is the Passover lamb or the Servant lamb of Isaiah 53:7 cannot be easily determined. There is some evidence that the two figures were combined very early in Christian thought.
“who takes away the sin of the world.” — The “world” designates humanity in its hostility to God, as elsewhere in this Gospel. Although not all persons without exception will be saved, the sacrifice is the only atonement for human sin, and its effectiveness is not limited by time or place.
“I did not know Him” (v.31). — Though John the Baptizer may have had previous personal contact with Jesus (cf. Luke 1:39–45), he did not know who Jesus was (the Lamb and Son of God) until the Spirit identified Him (v. 32).
“who baptizes with the Holy Spirit” (v.33). — The Old Testament anticipated the time of redemption as the time when the Spirit would be poured out on God’s people. Paul refers to Jesus as the second Adam who became “a life-giving spirit,” (1 Cor. 15:45). It is after Jesus returns to heaven that He sends this heavenly Helper to remind His Apostles of His teachings and guide them “into all truth” (14:26; 16:7,13).
“this is the Son of God” (v.34). — This is John’s way of reporting the heavenly voice that accompanied the heaven-sent Spirit, as recorded in Matt. 3:17, “This is my beloved Son, with whom I am well pleased.” While “son of God” was used variously by Jews (2 Sam. 7:14; Ps. 2:7) and Gentiles (Mark 15:39 note), the Baptizer’s witness, that of the last of the prophets of the old order (Matt. 11:11–14) is clear. Jesus is the Son of God, the “only Son from the Father” (v. 14).