John 1:8
He himself was not that Light, but came [only] to testify concerning that Light.
John 1:20
Then he declared openly, without denying it, "I am not the Christ [i.e., God's specially chosen one]."
John 3:28
You yourselves can testify that I said, 'I am not the Christ [i.e., God's specially chosen one] but [rather] that I was sent [by God] ahead of Him.'
Acts 19:4
Paul [then] said, "John immersed people who [demonstrated their] repentance, telling them they must believe in Jesus, the One who would come after him."
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
Then he declared openly, without denying it, "I am not the Christ [i.e., God's specially chosen one]."
John 3:28
You yourselves can testify that I said, 'I am not the Christ [i.e., God's specially chosen one] but [rather] that I was sent [by God] ahead of Him.'
Acts 19:4
Paul [then] said, "John immersed people who [demonstrated their] repentance, telling them they must believe in Jesus, the One who would come after him."
General references
Mark 11:30
Was the immersion of John [authorized] from heaven or from men? Give me an answer."
Acts 13:24
His coming occurred after John [the Immerser] had preached to Israel that those who repented should be immersed [as evidence that they had done so].