3 John
Third John is the shortest book in the New Testament, a personal note that opens a window onto the traveling missionaries and house churches of the first century. The elder writes to his friend Gaius, whose hospitality to workers for the truth has made him a fellow laborer in the gospel. In sharp contrast stands Diotrephes, who loves to be first, spreads malicious words, and shuts his door and his church to the brothers. Demetrius, warmly commended, completes the trio. Imitate good, not evil, the elder counsels, and hopes soon to speak face to face rather than with pen and ink.
The elder, traditionally identified with John the apostle
AD 85–100
Gaius, a faithful friend and host of traveling gospel workers
To commend Gaius's hospitality to gospel workers, censure the domineering Diotrephes, and commend Demetrius.