John Calvin on John 1:6

6. There was a man. The Evangelist now begins to discourse about the manner in which the Son of God was manifested in flesh; and that none may doubt that Christ is the eternal Son of God, he relates that Christ was announced by John the Baptist, as his herald. For not only did Christ exhibit himself to be seen by men, but he chose also to be made known by the testimony and doctrine of John; or rather, God the Father sent this witness before his Christ, that they might more willingly receive the salvation offered by him.

But it might at first sight appear ridiculous that Christ should receive testimony from another, as if he needed it; while, on the contrary, he declares that he does not seek testimony from man, (John 5:34.) The answer is easy and obvious, that this witness was appointed, not for the sake of Christ, but for our sake. If it be objected that the testimony of man is too weak to prove that Christ is the Son of God, it is likewise easy to reply, that the Baptist is not adduced as a private witness, but as one who, having received authority from God, sustained the character rather of an angel than of a man. Accordingly, he receives commendation not for his own virtues, but for this single circumstance, that he was the ambassador of God. Nor is this at variance with the fact, that the preaching of the gospel was committed to Christ, that he might be a witness to himself; for the design contemplated by the preaching of John was, that men might attend to the doctrine and miracles of Christ.

Sent by God. He does not say so for the purpose of confirming the baptism of John, but only mentions it in passing. This circumstance is not sufficient to produce certainty, since many run of their own accord, and boast that God has sent them; but the Evangelist, intending afterwards to speak more fully about this witness, reckoned it enough, for the present, to say in a single word, that John did not come but by the command of God. We shall afterwards see how he himself affirms that God is the Author of his ministry. We must now recollect — what I formerly noticed — that what is asserted about John is required in all the teachers of the Church, that they be called by God; so that the authority of teaching may not be founded on any other than on God alone.

Whose name was John. He states the name, not only for the purpose of pointing out the man, but because it was given to him in accordance with what he really was. There is no room to doubt that the Lord had reference to the office to which he appointed John, when he commanded by the angel that he should be so called, that by means of it all might acknowledge him to be the herald of divine grace. “Heraut et ambassade de la grace de Dieu;” — “Herald and ambassador of the grace of God.” For though the name יהוחנן “Le nom de Jean, qui signifie Grace;” — “The name John, which signifies Grace.” (Jehohannan) may be taken in a passive signification, and may thus be referred to the person, as denoting that John was acceptable to God; yet for my own part, I willingly extend it to the benefit which others ought to derive from him. For the meaning of the name John, derived from the Hebrew Jehohannan, the reader may consult our Author’s Commentary on the Harmony of the Three Evangelists, vol. i. page 15. — Ed.