This is he of whom I said, After me cometh a man which is preferred before me: for he was before me. And I knew him not: but that he should be made manifest to Israel, therefore am I come baptizing with water. And John bare record, saying, I saw the Spirit descending from heaven like a dove, and it abode upon him. And I knew him not: but he that sent me to baptize with water, the same said unto me, Upon whom thou shalt see the Spirit descending, and remaining on him, the same is he which baptizeth with the Holy Ghost. And I saw, and bare record that this is the Son of God. Joh 1:30-34
Living mostly apart, the one at Nazareth, the other in the Judean desert - to prevent all appearance of collusion, John only knew that at a definite time after his own call, his Master would show Himself. As He drew near for baptism one day, the last of all the crowd, the spirit of the Baptist heaving under a divine presentiment that the moment had at length arrived, and an air of unwonted serenity and dignity, not without traits, probably, of the family features, appearing in this Stranger, the Spirit said to him as to Samuel of his youthful type, “Arise, anoint Him, for this is He!” (1Sa 16:12) But the sign which he was told to expect was the visible descent of the Spirit upon Him as He emerged out of the baptismal water. Then, catching up the voice from heaven, “he saw and bare record that this is the Son of God.”
We can take note of some important points in these verses:
1. John proclaims that Jesus Was before. He Existed before John was born.
2. I knew him not. He knew not that God had chosen him to be the Christ. He knew, however, that he should be manifested in some way through his baptism.
3. I saw the Spirit descending from heaven like a dove. See Mat 3:16 It was revealed to John that the Christ would thus be revealed. Indeed it was the anointing of the Spirit that made Jesus the Anointed, the Christ.
Then the next day John makes the bold proclamation for all to hear:
Again the next day after John stood, and two of his disciples; And looking upon Jesus as he walked, he saith, Behold the Lamb of God! Joh 1:35-36