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.

For a witness - To give testimony. He came to prepare the minds of the people to receive him Matt. 3; Luke 3; to lead them by repentance to God; and to point out the Messiah to Israel when he came, John 1:31.
Of the Light - That is, of the Messiah. Compare Isaiah 60:1.
That all men - It was the object of John's testimony that all people might believe. He designed to prepare them for it; to announce that the Messiah was about to come, to direct the minds of men to him, and thus to prepare them to believe on him when he came. Thus, he baptized them, saying "That they should believe on him who should come after him" Acts 19:4, and thus he produced a very general expectation that the Messiah was about to come. The testimony of John was especially valuable on the following accounts:
1. It was made when he had no personal acquaintance with Jesus of Nazareth, and of course there could have been no collusion or agreement to deceive them, John 1:31.
2. It was sufficiently long before he came to excite general attention, and to fix the mind on it.
3. It was that of a man acknowledged by all to be a prophet of God - "for all men held John to be a prophet," Matthew 21:26.
4. It was "for the express purpose" of declaring beforehand that he was about to appear.
5. It was "disinterested."
He was himself extremely popular. Many were disposed to receive him as the Messiah. It was evidently in his "power" to form a large party, and to be regarded extensively as the Christ. This was the highest honor to which a Jew could aspire; and it shows the value of John's testimony, that he was willing to lay all his honors at the feet of Jesus, and to acknowledge that he was unworthy to perform for him the office of the humblest servant, Matthew 3:11.
Through him - Through John, or by means of his testimony.
Was not that Light - Was not "the Messiah." This is an explicit declaration designed to satisfy the disciples of John. The evidence that he was not the Messiah he states in the following verses.
From the conduct of John here we may learn,
1. The duty of laying all our honors at the feet of Jesus.
2. As John came that all might believe, so it is no less true of the ministry of Jesus himself. He came for a similar purpose, and we may all, therefore, trust in him for salvation.
3. We should not rely too much on ministers of the gospel. They cannot save us any more than John could; and their office, as his was, is simply to direct people "to the Lamb of God that taketh away the sin of the world."

That all men through him might believe - He testified that Jesus was the true light - the true teacher of the way to the kingdom of glory, and the lamb or sacrifice of God, which was to bear away the sin of the world, John 1:29, and invited men to believe in him for the remission of their sins, that they might receive the baptism of the Holy Ghost, John 1:32-34. This was bearing the most direct witness to the light which was now shining in the dark wilderness of Judea; and, from thence, shortly to be diffused over the whole world.

The same came for a witness, to bear witness of the Light, that all [men] (n) through him might believe.
(n) Through John.

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. This was one of the names of the Messiah with the Jews; of whom they say (u), , "light is his name"; as it is said in Daniel 2:22 and the light dwelleth with him; on which they have (w) elsewhere this gloss, this is the King Messiah; and so they interpret Psalm 43:3 of him (x). Philo the Jew often speaks of the Logos, or word, as light, and calls him the intelligible light; the universal light, the most perfect light; represents him as full of divine light; and says, he is called the sun (y). Now John came to bear a testimony to him, as he did; of which an account is given in this chapter, very largely, and elsewhere; as that he testified of his existence before his incarnation; of his being with the Father, and in his bosom: of his deity and divine sonship; of his being the Messiah; of the fulness of grace that was in him; of his incarnation and satisfaction; of his descent from heaven; and of his relation to his church, as in John 1:15 the end of which witness was,
that all men through him might believe; that is, that the Jews, to whom he preached, might, through his testimony, believe that Jesus was the light, and true Messiah; for these words are to be taken in a limited sense, and not to be extended, to every individual of mankind; since millions were dead before John began his testimony, and multitudes then in being, and since, whom it never reached: nor can it design more than the Jews, to whom alone he bore witness of Christ; and the faith which he taught, and required by his testimony, was an assent unto him as the Messiah; though the preaching of the Gospel is a means of true spiritual faith in Christ; and doubtless it was so to many, as preached by John: it points out the object of faith, and encourages souls to believe in Christ; and hence, Gospel ministers are instruments by whom ethers believe; and faith comes by hearing, and hearing by the word of God; and then is it, considerable end of the Gospel ministry answered,
(u) Echa Rabbati, fol. 50. 2. (w) Bereshit Rabba, fol. 1. 3. (x) Jarchi in ib. (y) De Maudi Opificio, p. 6. De Allegor. l. 2. p. 80. & de Somniis, p. 576, 578.

through him--John.

The same came for (that is, in order to give) a testimony - The evangelist, with the most strong and tender affection, interweaves his own testimony with that of John, by noble digressions, wherein he explains the office of the Baptist; partly premises and partly subjoins a farther explication to his short sentences. What St. Matthew, Mark, and Luke term the Gospel, in respect of the promise going before, St. John usually terms the testimony, intimating the certain knowledge of the relator; to testify of the light - Of Christ.