The epistle’s title is “3 John.” It is the third in a series of 3 epistles that bear the Apostle John’s name. Third John and 2 John present the closest approximation in the New Testament to the conventional letter form of the contemporary Greco-Roman world, since they were addressed from an individual to individuals. Both 2 and 3 John are the shortest epistles in the NT, each containing less than 300 Greek words, so as to fit on a single papyrus sheet (cf. v. 13).
Third John is perhaps the most personal of John’s 3 epistles. While 1 John appears to be a general letter addressed to congregations scattered throughout Asia Minor, and 2 John was sent to a lady and her family (2 John 1), in 3 John the apostle clearly names the sole recipient as “the beloved Gaius” (v. 1). This makes the epistle one of a few letters in the NT addressed strictly to an individual (cf. Philemon). The name “Gaius” was very common in the first century (e.g., Acts 19:29; 20:4; Rom. 16:23; 1 Cor. 1:14), but nothing is known of this individual beyond John’s salutation, from which it is inferred that he was a member of one of the churches under John’s spiritual oversight.

As with 2 John, 3 John focuses on the basic issue of hospitality but from a different perspective. While 2 John warns against showing hospitality to false teachers (2 John 7–11), 3 John condemns the lack of hospitality shown to faithful ministers of the Word (vv. 9,10). Reports came back to the apostle that itinerant teachers known and approved by him (vv. 5–8) had traveled to a certain congregation where they were refused hospitality (e.g., lodging and provision) by an individual named Diotrephes who domineered the assembly (v. 10). Diotrephes went even further, for he also verbally slandered the Apostle John with malicious accusations and excluded anyone from the assembly who dared challenge him (v. 10).

In contrast, Gaius, a beloved friend of the apostle and faithful adherent to the truth (vv. 1–4), extended the correct standard of Christian hospitality to itinerant ministers. John wrote to commend the type of hospitality exhibited by Gaius to worthy representatives of the gospel (vv. 6–8) and to condemn the high-handed actions of Diotrephes (v. 10). The apostle promised to correct the situation personally and sent this letter through an individual named Demetrius, whom he commended for his good testimony among the brethren (vv. 10–12).