John Calvin Commentary John 3:28

"Ye yourselves bear me witness, that I said, I am not the Christ, but, that I am sent before him." — John 3:28 (ASV)

You are witnesses to me. John earnestly reasons with his disciples that they did not believe his statements. He had often warned them that he was not the Christ; and, therefore, it only remained for him to be a servant and subject to the Son of God along with others. And this passage is noteworthy; for, by affirming that he is not the Christ, he reserves nothing for himself except to be subject to the Head, to serve in the Church as one of the others, and not to be so highly exalted as to obscure the honor of the Head. He says that he was sent before, to prepare the way for Christ, as kings are accustomed to have heralds or forerunners.