John the Apostle
John 1:7BSB·traditional attribution

He came as a witness to testify about the Light, so that through him everyone might believe.

John Calvin Reformed @genevareformer

7. He came for a testimony. The end of his calling is briefly noticed; which was, that he might prepare a Church for Christ, as, by inviting all to Christ, he shows plainly enough that he did not come on his own account.

Matthew Henry Presbyterian @wholebiblehenry

The evangelist designs to bring in John Baptist bearing an honourable testimony to Jesus Christ, Now in these verses, before he does this, I. He gives us some account of the witness he is about to produce. His name was John, which signifies gracious; his conversation was austere, but he was not the less gracious. Now, 1.

Commenting on John 1:6-14

John Gill Reformed Baptist @doctorgill

The same came for a witness,.... The end of his being sent, and the design of his coming were, to bear witness of the light: by which is meant, not the light of nature, or reason; nor the light of the Gospel: but Christ himself, the author of light, natural, spiritual, and eternal.