John 1:8

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

John 1:20

And he confessed and denied not, but confessed, I am not the Christ.

John 3:28

Ye yourselves are my witnesses that I said, I am not the Christ, but that I am sent before him.

Acts 19:4

Then said Paul, John verily baptized with the baptism of repentance, saying unto the people that they should believe on him who should come after him, that is, on Christ, Jesus.

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
And he confessed and denied not, but confessed, I am not the Christ.
John 3:28
Ye yourselves are my witnesses that I said, I am not the Christ, but that I am sent before him.
Acts 19:4
Then said Paul, John verily baptized with the baptism of repentance, saying unto the people that they should believe on him who should come after him, that is, on Christ, Jesus.

General references

Mark 11:30
The baptism of John, was it of heaven or of men? Respond unto me.
Acts 13:24
John, having first proclaimed before his coming, the baptism of repentance to all the people of Israel.