John 1:8

Not being the light he came to give a witness of it.

John 1:20

He said: I am not the Christ.

John 3:28

You bear witness that I said I am not the Christ. I have been sent before him.

Acts 19:4

Paul said: John baptized with the baptism of repentance. He told the people they should believe in Jesus, the one who came after John.

Treasury of Scripture Knowledge

Summary

He was not that Light, but was sent to bear witness of that Light.

General references

Bible References

That light

John 1:20
He said: I am not the Christ.
John 3:28
You bear witness that I said I am not the Christ. I have been sent before him.
Acts 19:4
Paul said: John baptized with the baptism of repentance. He told the people they should believe in Jesus, the one who came after John.

General references

Mark 11:30
The baptism of John was it from heaven or from men? Give me an answer.
Acts 13:24
Before Jesus came John preached the baptism of repentance to all the people of Israel.