Author: Just like in 1 John, the author only identifies himself as “the elder.” There is every reason to believe that this is the apostle John as he was an elder in the Ephesian church and he was “the elder” by virtue of the fact that he was the only living apostle by the time that he wrote this letter.
Aside from the name, there is strong reason to believe that John wrote this letter as it has many similarities to the other letters and gospel that bear his name.
Recipients: A man by the name of Gaius is addressed in this letter. This was a very common Roman name and his identity is otherwise unknown. He would appear to be a Christian in one of the churches of Asia Minor, most likely near the Ephesian church.
Like other Biblical letters, while one person was addressed, this was circulated around to other churches as its message was important for all Christians.
Date: 3 John is obviously written after John’s first two letters but it is believed that all three letters were written near the same time. This was most likely after the writing of the gospel of John and is toward the end of John’s life, somewhere between 85-95 AD.
Message: The message of 3 John stands in contrast to 2 John. While 2 John warned the recipients not to accept Gnostic teachers within their homes, it appears that some of John’s disciples were not being accepted by the church. Worse yet, a man by the name of Diotrephes was kicking people out of the church who aided John’s disciples.
John condemns Diotrephes while commending a man by the name of Demetrius.
Key verse: 3 John 11: “Dear friend, do not imitate what is evil but what is good. Anyone who does what is good is from God. Anyone who does what is evil has not seen God.”