John 1:20
And he confessed, and denied not; but confessed, I am not the Christ.
Matthew 3:11-12
I indeed baptize you with water unto repentance: but he that comes after me is mightier than I, whose shoes I am not worthy to bear: he shall baptize you with the Holy Spirit, and with fire:
Mark 1:7-8
And preached, saying, There comes one mightier than I after me, the thong of whose sandals I am not worthy to stoop down and unloose.
Luke 3:15-17
And as the people were in expectation, and all men questioned in their hearts concerning John, whether he was the Christ, or not;
John 3:28-36
You yourselves bear me witness, that I said, I am not the Christ, but that I am sent before him.