John 1:31

I myself did not know him, but, that he may be made known to Israel, I have come, baptizing with water."

Luke 1:17

He shall go before him in the spirit and with the power of Elijah, 'to reconcile fathers to their children' and the disobedient to the wisdom of the righteous, and so make ready for the Lord a people prepared for him."

Matthew 3:6

And were baptized by him in the river Jordan, confessing their sins.

Mark 1:3-5

'The voice of one crying aloud in the Wilderness: "Make ready the way of the Lord, Make his paths straight."'

Luke 1:76-80

And thou, Child, shalt be called Prophet of the Most High, For thou shalt go before the Lord to make ready his way,

Luke 2:39-42

When the child's parents had done everything enjoined by the Law of the Lord, they returned to Galilee to their own town of Nazareth.

Luke 3:3-4

And John went through the whole district of the Jordan, proclaiming baptism upon repentance, for the forgiveness of sins.

John 1:7

He came as a witness--to bear witness to the Light that through him all men might believe.

John 1:33

I myself did not know him, but he who sent me to baptize with water, he said to me 'He upon whom you see the Spirit descending, and remaining upon him--he it is who baptizes with the Holy Spirit.'

Acts 19:4

"John's baptism was a baptism upon repentance," rejoined Paul, "and John told the people (speaking of the 'One Coming; after him) that they should believe in him--that is in Jesus."

Treasury of Scripture Knowledge

Summary

And I knew him not: but that he should be made manifest to Israel, therefore am I come baptizing with water.

Bible References

I knew

John 1:33
I myself did not know him, but he who sent me to baptize with water, he said to me 'He upon whom you see the Spirit descending, and remaining upon him--he it is who baptizes with the Holy Spirit.'
Luke 1:80
The child grew and became strong in spirit; and he lived in the Wilds till the time came for his appearance before Israel.
Luke 2:39
When the child's parents had done everything enjoined by the Law of the Lord, they returned to Galilee to their own town of Nazareth.

But

John 1:7
He came as a witness--to bear witness to the Light that through him all men might believe.
Luke 1:17
He shall go before him in the spirit and with the power of Elijah, 'to reconcile fathers to their children' and the disobedient to the wisdom of the righteous, and so make ready for the Lord a people prepared for him."

Therefore

Matthew 3:6
And were baptized by him in the river Jordan, confessing their sins.
Mark 1:3
'The voice of one crying aloud in the Wilderness: "Make ready the way of the Lord, Make his paths straight."'
Luke 3:3
And John went through the whole district of the Jordan, proclaiming baptism upon repentance, for the forgiveness of sins.
Acts 19:4
"John's baptism was a baptism upon repentance," rejoined Paul, "and John told the people (speaking of the 'One Coming; after him) that they should believe in him--that is in Jesus."