John Gill Commentary 3 John 1

The elder unto the well beloved Gaius
The elder is the writer of the epistle, the Apostle John, who so styles himself on account of his age, and office, as in the preceding epistle. The person to whom he writes is "the well beloved Gaius"; not that Gaius, who was the Apostle Paul's host, (Romans 16:23) , for though their characters agree, being both hospitable men, yet neither the place nor time in which they lived. The Apostle Paul's Gaius lived at Corinth, this is in some place near to Ephesus, for the apostle in his old age purposed to come and see him shortly; the other was contemporary with Paul, this with John; there were thirty or forty years difference between them: besides, the Corinthian Gaius was baptized by Paul, and was doubtless one of his spiritual children, or converts, whereas this Gaius was one of the Apostle John's spiritual children, (3 John 1:4) ; nor does he seem to be the same with Gaius of Macedonia, (Acts 19:29) , or with Gaius of Derbe, (Acts 20:4) , who seem to be two different persons by their country, though both companions in travel of the Apostle Paul; for which reason, as well as the time of their living, neither of them can be this Gaius, who was a settled housekeeper, and resided at some certain place.

His name is a Roman name, and the same with Caius, though he seems to have been a Jew, as he might, it being usual with the Jews in other countries to take Gentile names. His character is, that he was "well beloved"; that is, of God, as it appears he was from the grace bestowed on him, from the prosperous estate of his soul, and from the truth that was in him, and his walking in it; and of the Lord Jesus Christ, for the same reasons; and also of all the brethren and saints that knew him; he being a person not only truly gracious, and of faithfulness and integrity, but of great liberality and beneficence, which must gain him much love and esteem among them; and he was well beloved by the Apostle John; and so the Syriac version renders it, "to my beloved Gaius": though his love to him is expressed in the following clause,

whom I love in the truth ;
as being in it, or for the sake of it, or truly and sincerely; (See Gill on 2 John 1:1).

Beloved, I wish above all things that you may prosper ,
&c.] Or succeed in all temporal affairs, in the business of life, in which he was; and as success of this sort depends upon the blessing of God, which makes rich, it is to be wished and prayed for from him:

and be in health ;
that is, of body, which above all things above all outward mercies, is the most desirable; for without this, what are the richest dainties, the largest possessions, or the best of friends? without this there can be no comfortable enjoyment of either of them; and therefore of this sort of mercies, it is in the first place, and above all others, to be wished for, and desired by one friend for another. The rule and measure of this wish is according to the prosperity of his soul,

even as your soul prospers :
the soul is diseased with sin, and may be said to be in good health, when all its iniquities are forgiven; and may be said to prosper, when having a spiritual appetite for the Gospel, the sincere milk of the word, it feeds upon it, is nourished by it, and grows thereby; when it is in the lively exercise of faith, hope, and love; when spiritual knowledge is increased, or it grows in grace, and in the knowledge of Christ Jesus; when the inward man is renewed day by day with fresh strength; and when it enjoys communion with God, has the light of his countenance, and the joys of his salvation; and when it is fruitful in every good work.

For I rejoiced greatly when the brethren came
From the place where Gaius lived, to that where John now resided; these brethren seem to be preachers of the word, who travelled from place to place to spread the Gospel:

and testified of the truth that is in you ;
either of Christ, who was formed in him; or of the Gospel, which had a place in his heart; or of the truth of grace that was in him, as well as of that faithfulness, integrity, and sincerity he appeared to be possessed of, being an Israelite indeed, and without guile:

even as you walk in the truth :
in Christ, and in the Gospel, and as became it, and with all uprightness; see (2 John 1:4) ; and this occasioned great joy in the apostle; as it is matter of joy to every one that truly loves Christ, and his Gospel; or has the true grace of charity in him, which envies not the gifts and graces of others, but rejoices in the truth, wherever it is found; and especially to the faithful ministers of the word, when they hear of the truth of grace in any souls, and that such continue walking in the truth of the Gospel, and particularly those who have been wrought upon under their ministry, as follows.

I have no greater joy
Nothing that causes greater joy. The Vulgate Latin version reads "grace" or "thanks"; and then the sense is, that he had nothing to be more thankful for:

than to hear that my children walk in truth ;
meaning his spiritual children, those whose conversion he had been the instrument of; and among these it seems Gaius was one.

Beloved, thou doest faithfully Or a faithful thing, and as became a faithful man, a believer in Christ; in all his beneficence and charity he acted the upright part; he did not do it in an hypocritical way, to be seen of men, and gain applause from them, but from a principle of love, and with a view to the glory of God:

whatsoever thou doest to the brethren, and to strangers which may design either different persons; and by "brethren" may be meant the poor brethren of the church that. Gaius belonged to, and others that were well known to him; and by "the strangers", not unconverted persons, but such of the saints as came from foreign parts, and travelled about to spread the Gospel, and enlarge the interest of Christ: or else the same persons may be intended, for the words may be read, as they are in the Alexandrian copy, and some others, and in the Vulgate Latin version, "what thou doest to the brethren, and this to strangers"; that is, as the Arabic version renders it, "to strange brethren"; or, as the Syriac version, "to the brethren, [and] especially [them] that are strangers"; so that Gaius was a very hospitable man, one that entertained and lodged strangers, and used them very civilly and courteously, with great liberality, and with much integrity and sincerity.