The third letter of John shows the tenderness of love that comes to expression in the support towards those who have gone forth for the sake of the truth. It is the other side of what you have seen in the second letter. That letter deals more with the steadfastness of love in refusing to give hospitality to false teachers. You may summarize the message of the second letter in the words: ‘Do not receive!’ (2Jn 1:10) and of the third letter in the word: ‘Receive!’ (3Jn 1:8).
If we would only have had the second letter, we would run the risk to become strict, insensitive and suspicious. Therefore the third letter is a necessary and at the same time wonderful supplement to the second letter. It causes the balance that is necessary in the judgment of what presents itself as being Christian.
Besides the order to receive the true servant of God, this letter also gives a vivid picture of the church life in the second part of the first century, with timeless instructions for the people of God.
It is also remarkable that in this letter the name of the Lord Jesus is not mentioned. You indeed find a general reference to ‘the Name’ (3Jn 1:7).
With some characteristics John portrays some people: the hospitable and spiritual Gaius, the commendable Demetrius and the self-interested uncompassionate Diotrephes. That also gives a good division of this letter:
1. Greeting (3 John 1:1-4).
2. The God fearing Gaius (3 John 1:5-8).
3. The dictator Diotrephes (3 John 1:9-11).
4. The pious Demetrius (3 John 1:12).
5. The plans of the apostle and blessing (3 John 1:13-14).