John 1:6

Having before Explained about God the Word, and most accurately gone through the things whereby He is shown to be by Nature Son of God the Father, he fortifies their faith in what they had already heard by his words. And since (according to what was said by God through Moses), At the mouth of two and three witnesses shall every word be established, wisely does he bring in addition to himself the blessed Baptist, and introduces him along with himself a most noteworthy witness. For he did not suppose that he ought, even if of gravest weight, to demand of the readers in his book concerning our Saviour credence above that of the law, and that they should believe him by himself when declaring things above our understanding and sense. Therefore the blessed Evangelist himself testifies that The Word was in the beginning and the Word was God and was in the beginning with God and that all things were made by Him, and He was in the things made as Life, and that the Life was the Light of men, that by all these he might show that the Son is by Nature God. And the Divine Baptist too testifies in addition to him, crying aloud, Prepare ye the way of the Lord, make straight the paths of our God. For soothly one will say that He is Very God, in Whom is by Nature inherent the dignity of lordship and it accrues not to any other rightly and truly, since to us there is one God the Father, and one Lord Jesus Christ, as Paul saith; and though there be many called gods by grace and lords both in heaven and earth, yet the Son is One with the Father Very God. Therefore, most noteworthy is the pair of holy witnesses, and credence no longer capable of blame is due to the things said, both as having received the fulness of the law, and supported by the notability of the persons. […]

Having in the introduction spoken to us things of urgent importance concerning God the Word, (the Evangelist) proceeding on his road, and in order, afterwards comes to the herald of the Word, his namesake John. And now that thou hearest that he was "sent from God," do not for the future imagine that any of the words spoken by him are mere man's words; for all that he utters is not his own, but is of Him who sent him. Wherefore he is called "messenger" (Mal. iii. 1), for the excellence of a messenger is, that he say nothing of his own. But the expression "was," in this place is not significative of his coming into existence, but refers to his office of messenger; for "'there was' a man sent from God," is used instead of "a man 'was sent' from God."

Where we say "sent," the Hebrew says, "one sent forth"; in Greek apostolos, in Hebrew siloas. You see, therefore, that this John, the prophet, is not only a prophet but also an apostle. Isaiah is sent; he was an apostle. "Here I am, send me!" "Sent" is a term well said.… Those who have come on their own authority and have not been sent are the thieves and robbers. But this man has been sent from God, "whose name was John" and whose name corresponds to his calling. The name "Ioannes" is interpreted as the grace of the Lord, for io means Lord, and anna means grace. And so John is called the grace of the Lord. His mission as messenger he receives from the Lord.

Not an Angel, as many have held. The Evangelist here refutes such a notion.

Having told us about the pre-eternal existence of God the Word and intending to speak about the incarnation of the Word, the Evangelist inserts a discourse about the Forerunner. And what else, if not the birth of John the Forerunner, could be spoken of before …

"There was a man sent from God, whose name was John." He treated above of the Word according to the excellence of the Divinity; in this part he treats according to the assumption of humanity. And because this assumption was made for our salvation, which …

That is, the grace of God, or one in whom is grace, who by his testimony first made known to the world the grace of the New Testament, that is, Christ. Or John may be taken to mean, to whom it is given: because that through the grace of God, to him it was given, not only to herald, but also to baptize the King of kings.

Above, the Evangelist considered the divinity of the Word; here he begins to consider the incarnation of the Word. And he does two things concerning this: first, he treats of the witness to the incarnate Word, or the precursor; secondly, of the coming of the …

There was a man sent from God,....

John, after beginning his gospel with a statement of our Lord's nature as God, proceeds to speak of His forerunner, John the Baptist. The contrast between the language used about the Savior, and that used about His forerunner, ought not to be overlooked. Of Christ we are told that He was the eternal God—the Creator of all things—the source of life and light. Of John the Baptist we are told simply, that "there was a man sent from God, whose name was John." We see, firstly, in these verses, the true nature of a Christian minister's office.

John, after beginning his gospel with a statement of our Lord's nature as God, proceeds to speak of His forerunner, John the Baptist. The contrast between the language used about the Savior, and that used about His forerunner, ought not to be overlooked. Of Christ we are told that He was the eternal God—the Creator of all things—the source of life and light. Of John the Baptist we are told simply, that "there was a man sent from God, whose name was John." We see, firstly, in these verses, the true nature of a Christian minister's office. We have it in the description of John the Baptist—"He came for a witness, to bear witness of the light, that all men through him might believe." Christian ministers are not priests, nor mediators between God and man. They are not agents into whose hands men may commit their souls, and carry on their religion by deputy. They are witnesses. They are intended to bear testimony to God's truth, and specially to the great truth that Christ is the only Savior and light of the world. This was Peter's ministry on the day of Pentecost. "With many other words did he testify ." (Acts 2:40.) This was the whole tenor of Paul's ministry. "He testified both to the Jews and Greeks repentance towards God, and faith towards our Lord Jesus Christ." (Acts 20:21.) Unless a Christian minister bears a full testimony to Christ, he is not faithful to his office. So long as he does testify of Christ, he has done his part, and will receive his reward, although his hearers may not believe his testimony. Until a minister's hearers believe on that Christ of whom they are told, they receive no benefit from the ministry. They may be pleased and interested; but they are not profited until they believe. The great end of a minister's testimony is "that through him, men may believe."

Whose name was John - This was John the Baptist; see his name and the nature of his office explained, Mar 1:4 (note), and Mat 3:1-3 (note).

A man sent from God - See Matt. 3. The evangelist proceeds now to show that John the Baptist was not the Messiah and to state the true nature of his office. Many had supposed that he was the Christ, but this opinion he corrects; yet he admits that he was “sent from God” - that he was divinely commissioned. Though he denied that he was “the Messiah,” yet he did not deny that he was sent from or by heaven on an important errand to human beings. Some have supposed that the sole design of this gospel was to show that John the Baptist was not the Messiah. Though there is no foundation for this opinion, yet there is no doubt that one object was to show this. The main design was to show that “Jesus was the Christ,” Joh 20:31. To do this, it was proper, in the beginning, to prove that “John” was not the Messiah; and this might have been at that time an important object. John made many disciples, Mat 3:5. Many persons supposed that he might be the Messiah, Luk 3:15; Joh 1:19. “Many of these disciples of John remained” at Ephesus, “the very place where John is supposed to have written this gospel, long after the ascension of Jesus,” Act 19:1-3. It is not improbable that there might have been many others who adhered to John, and perhaps many who supposed that he was the Messiah. On these accounts it was important for the evangelist to show that John “was not the Christ,” and to show, also, that he, who was extensively admitted to be a prophet, was an important “witness” to prove that Jesus of Nazareth was the Christ. The evangelist in the first four verses stated that “the Word” was divine; he now proceeds to state the proof that he was a “man,” and was the Messiah. The first evidence adduced is the testimony of John the Baptist.