I. The sacred penman writes and sends the letter, referred to as "The elder," meaning by years and office, deserving honor. Some question whether this was John the apostle, but his style and spirit are evident. Gaius could not question who wrote it. John humbly refers to himself as "the elder," aligning with ordinary church pastors. II. The recipient is Gaius, a well-beloved individual, possibly the same Gaius mentioned by Paul in Romans 16:23. John expresses his love for him "in the truth," for walking in truth, which shows true love rooted in the gospel. III. John prays for Gaius, asking for the prosperity of both his soul and body. Soul prosperity is the greatest blessing, often housed in a fragile body, but the desire for both spiritual and physical well-being is evident.

I. John receives a good report of Gaius's faith and charity from the brethren. Gaius’s love for the brethren and hospitality to strangers proves his sincerity in the faith. II. Gaius is commended for his hospitality, a virtue extended to strangers and those of different churches. III. John expresses great joy in hearing of Gaius's walk in truth. This reflects the joy of ministers when they see their followers living out their faith. IV. John advises Gaius to continue supporting the brethren by aiding them on their journeys in a godly manner, reflecting Christian generosity. V. The brethren went forth preaching for God's sake, taking nothing from the Gentiles. John emphasizes the need for the church to support such ministers, as they help propagate the truth.

I. Diotrephes, unlike Gaius, loved preeminence and refused apostolic authority, spreading malicious words. He did not accept John’s letter and discouraged others from showing hospitality, casting them out of the church. John warns that he will address this behavior when he visits. II. John cautions against following Diotrephes’ evil example and encourages believers to imitate what is good, for those who do good are of God, while those who do evil have not seen God.

I. Demetrius, on the other hand, has a good report from all and of the truth itself. John and others also bear witness to his character, and Gaius can trust this testimony. Demetrius was likely well known to both John’s church and Gaius's. II. John closes the letter expressing a desire to see Gaius soon and wishing him peace. He also sends greetings from mutual friends and instructs Gaius to greet their friends by name, indicating a personal connection.