3 John is the antepenultimate book of the New Testament. It is a private letter composed to a man named Gaius, recommending to him a group of Christians led by Demetrius, which had come to preach the gospel in the area where Gaius lived. The purpose of the letter is to encourage and strengthen Gaius, and to warn him against Diotrephes, who refuses to cooperate with the author of the letter.
Early church literature contains no mention of the epistle, with the first reference to it appearing in the middle of the third century. This lack of documentation caused early church writers to doubt its authenticity until the early 5th century, when it was accepted into the canon along with the other two epistles of John.
Year: 90-120 AD