John 1:8

He was not the Light; it was to bear testimony to the Light that he appeared.

John 1:20

he frankly confessed ??he did not deny it, he frankly confessed, "I am not the Christ."

John 3:28

You can bear me out, that I said, 'I am not the Christ'; what I said was, 'I have been sent in advance of him.'

Acts 19:4

"John," said Paul, "baptized with a baptism of repentance, telling the people to believe in Him who was to come after him, that is, in 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
he frankly confessed ??he did not deny it, he frankly confessed, "I am not the Christ."
John 3:28
You can bear me out, that I said, 'I am not the Christ'; what I said was, 'I have been sent in advance of him.'
Acts 19:4
"John," said Paul, "baptized with a baptism of repentance, telling the people to believe in Him who was to come after him, that is, in Jesus."

General references

Mark 11:30
What about the baptism of John? Was it from heaven or from men?"
Acts 13:24
before whose coming John had already preached a baptism of repentance for all the people of Israel.