John 1:31

I did not know Him myself, but I came baptizing in water, that He might be made known to Israel."

Luke 1:17

He will go before Him in the spirit and the power of Elijah to turn the hearts of fathers to their children and the disobedient to the wisdom of the upright, to make ready for the Lord a people perfectly prepared."

Matthew 3:6

and were baptized by him in the Jordan River, as one by one they continued to confess their sins.

Mark 1:3-5

He is a voice of one who shouts in the desert, 'Get the road ready for the Lord; make the paths straight for Him.'"

Luke 1:76-80

And you, my child, will be called a prophet of the Most High, for you will go before the Lord to make ready His ways,

Luke 2:39-42

Now when they had completed everything that was in accordance with the law of the Lord, they returned to Galilee, to their own town of Nazareth.

Luke 3:3-4

And he went all over the Jordan valley, preaching a baptism conditioned on repentance to obtain the forgiveness of sins,

John 1:7

He came for the purpose of testifying, to testify to the light, so that everyone through him might come to believe.

John 1:33

I did not know Him myself, but the very One who sent me to baptize in water said to me, 'The One on whom you see the Spirit coming down and remaining, is the One who is to baptize in the Holy Spirit.'

Acts 19:4

Then Paul said, "John baptized with a baptism that was an expression of repentance, telling the people to believe in Him who was to come after 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 did not know Him myself, but the very One who sent me to baptize in water said to me, 'The One on whom you see the Spirit coming down and remaining, is the One who is to baptize in the Holy Spirit.'
Luke 1:80
Now the child continued to grow and to gain strength in the Spirit, and he lived in the desert until the day when he announced himself to Israel.
Luke 2:39
Now when they had completed everything that was in accordance with the law of the Lord, they returned to Galilee, to their own town of Nazareth.

But

John 1:7
He came for the purpose of testifying, to testify to the light, so that everyone through him might come to believe.
Luke 1:17
He will go before Him in the spirit and the power of Elijah to turn the hearts of fathers to their children and the disobedient to the wisdom of the upright, to make ready for the Lord a people perfectly prepared."

Therefore

Matthew 3:6
and were baptized by him in the Jordan River, as one by one they continued to confess their sins.
Mark 1:3
He is a voice of one who shouts in the desert, 'Get the road ready for the Lord; make the paths straight for Him.'"
Luke 3:3
And he went all over the Jordan valley, preaching a baptism conditioned on repentance to obtain the forgiveness of sins,
Acts 19:4
Then Paul said, "John baptized with a baptism that was an expression of repentance, telling the people to believe in Him who was to come after him; that is, in Jesus."