This third letter was probably written about the same time as the second and is addressed to Gaius who we do not know much about.
As we saw in 2 John there were warnings about accepting traveling teachers who were not teaching the truth, it seems that the opposite was happening here. John praises Gaius for his faithfulness in serving his fellow believers and doing what is right, but has firm words to say about Diotrephes who it seems was obstructing John’s word.
Gaius was looking after “the brothers” even though they were not known personally to him. He faithfully served his local church as well as those who passed through his home with an example of good hospitality.
Diotrephes was apparently leader of a fellowship group and as such seemed to enjoy too much power in that he was able to exclude those sent by John, spreading lies about them and excluding anyone of the fellow believers who wished receive and support them. John says that he has written to the church but Diotrephes will not pay any attention to it, acting in a dictatorial manner.
In contrast, Demetrius is highly commended by everyone who knows him and is shown as a good example for the believers to follow. He was possibly the carrier of the letter.
So his key message in this letter is;
My dear friend, do not imitate what is bad, but imitate what is good. Whoever does good belongs to God, whoever does what is bad has not seen God (v11)
Perhaps Diotrephes was the leader of the same church group or certainly closely associated to the group that Gaius belonged to. Perhaps Gaius was one who Diotrephes was attempting to exclude? I don’t know as we don’t know any more specific details, but John wished to encourage Gaius to continue his faithful work and follow the example of Demetrius rather than Diotrephes.
It is interesting to compare 2 John and 3 John together. In one letter we see that perhaps “the lady” was too kindhearted and risked being lead astray. In the other we hear of a man who is too dominant and is not prepared to accept any help or other teaching – he knows it all. Both are a warning to us to be both gentle and wise. We can easily become either too dogmatic that we are no longer willing to learn or too “soft” in that we risk being carried away with whatever the latest fashion is.
Quotes from The Good News Bible