As in the second epistle, John calls himself "the elder". He is in his nineties, so it might refer to his age, but more likely to the fact that he is a presbyter, elder or overseer of his local church.
He is writing to a fellow-believer who is also a personal friend, called Gaius. Four times John calls him "beloved" (vv. 1,2,5,11), and says he loves him "in the truth" (see 2 John). Immediately we are told that Gaius was a man who had the truth in him, and walked in the truth: he not only stood for the truth, accepted the deity of Christ and was sound in doctrine, but he also worked for the truth. He walked and worked in love. He manifested love. One has to think right in order to act right, and that is true in any sphere of life today.
John evidently thought a great deal of Gaius and was very close to him. He made it clear that he wanted Gaius to prosper not only spiritually, of which he had ample evidence, but also in all things, materially and healthwise.
There are a lot of Christians today who prosper materially and enjoy good health, but are sick spiritually. They have the wrong priorities. What physical health is to the body, holiness is to the spiritual life of the believer. To be healthy spiritually is to be holy: it is to be growing in grace and in the knowledge of Christ, not only improving in conduct but learning the doctrines of our faith.
Gaius would open his home to men who came from other places to teach the Word of God. He not only walked in love, but he also walked in truth, and that means he tested these teachers. Gaius was able to tell who were the genuine believers and who were not, by finding out what they thought of the person of Jesus Christ. One must think rightly of Him in order to be right in everything else. Many of these travelling evangelists and missionaries reported to John the graciousness of Gaius and his walk in the doctrine and the teaching of the apostles.
It was a great joy to John to hear that one of his converts was walking in truth. His conduct conformed to his doctrine. From verse 5 to 8, John commended Gaius for having received and entertained the true teachers of the Word.
Whereas in his second letter John the apostle warned against receiving false teachers, in this letter he encourages believers to receive the true brethren. Many of us have been disappointed and deceived by false pastors and teachers, but we should not let that deter us from supporting that which we know is of the Lord.
We should not support anything (including a church or a radio ministry) until we are sure that it is of God and that the Word of God is being given out. If we help those who are giving out the Word of God and who are walking in love, we do well.
These men who were received by Gaius went out at great sacrifice. They didn't receive a salary or any remuneration. They went out trusting the Lord, and homes were opened to them. In some places they were given support; in other places they were not. They took nothing of the Gentiles: this is another way of testing that which is genuine or not.
Religious rackets try to get every Tom, Dick, and Harry, believers or not, to donate to the cause. But the work of the Lord depends only on the Lord's people. These true men would take nothing of the Gentiles, that is, from unbelievers. Unbelievers should never be asked to support the Lord's work. As the ark could only be carried on the shoulders of the priests, so only the believers (who are all priests) are to carry the Lord Jesus Christ into this world today.
When a man is doing God's work, he should be supported by us. In that way we become partners with him in getting out the Word of God.
1 The elder to the beloved Ga'ius, whom I love in the truth.
2 Beloved, I pray that all may go well with you and that you may be in health; I know that it is well with your soul.
3 For I greatly rejoiced when some of the brethren arrived and testified to the truth of your life, as indeed you do follow the truth.
4 No greater joy can I have than this, to hear that my children follow the truth.
5 Beloved, it is a loyal thing you do when you render any service to the brethren, especially to strangers,
6 who have testified to your love before the church. You will do well to send them on their journey as befits God's service.
7 For they have set out for his sake and have accepted nothing from the heathen.
8 So we ought to support such men, that we may be fellow workers in the truth.