Author

In both Second and Third John, the author identifies himself only as "The elder". The overwhelming evidence from both internal and external evidence that this "elder" is the apostle John has led conservative scholars to unanimously recognize him as the writer. As to internal evidence, the words, grammar, and ideas of Third John are closely related to First John. Concerning the external evidence, the ancient writers Clement of Alexandria, Dionysius, and Cyprian are all witnesses to the authorship of John.

Relationships Between First, Second, and Third John

1. First John shows how to have fellowship with God and the brethren. - 1 John 1:3, 6-7
2. Second John shows the limits of that fellowship. - 2 John 9
3. Third John shows the practical application of that fellowship to the brethren - 3 John 5-8
4. A key theme of First John is walking "in the light" (1 John 1:7). A key theme of Third John is "walk in truth" (verses 3-4)
5. Key Words (i.e., thoughts) Common to First, Second, and Third John
   

   Word	Occurrences in First John	Occurrences in Second John	Occurrences in Third John
   Beloved	5		4
   children	15	2	1
   love	29	4	2
   truth (true)	10	4	7
   walk	5	3	2
   walk(ing) in truth		1	2
   is of God	2		1

6. The thought of Second John 4 and Third John 3-4 are virtually identical.
7. Third John 5-8 is the "flip side" of Second John 9-11. Second John 9-11 forbids giving assistance to false teachers, whereas Third John 5-8 commends giving assistance to those who preach the truth.
8. Third John 13-14a is practically a repetition of Second John 12.

From Where Written

unknown, but perhaps Ephesus

When Written

unknown, but undoubtedly late first century

To Whom Written

A Christian named "Gaius" (common Roman name, unknown other than name) - 3 John 1; Acts 19:29; 20:4; Romans 16:23; 1 Corinthians 1:14

Purpose of the Letter

The apostle commends Gaius for assisting faithful brethren, encourages him to continue this practice, and condemns Diotrophes for refusing to assist them

Theme

We should assist those who preach the truth

Outline

1. Introduction - verses 1-4
   ..a. John addresses Gaius. - verse 1
   ..b. John prays for Gaius. - verse 2
   ..c. Gaius' "walk in truth" gives John great joy. - verses 3-4
2. Gaius Commended (We ought to support preachers of the truth.) - verses 5-8
3. Diotrophes Condemned (He loved to have the preeminence and refused to receive preachers of the truth.) - verses 9-10
4. Demetrius a Good Example (Demetrius unknown other than name - cf. Acts 19:24, 38) - verses 11-12
5. Conclusion - verses 13-14
   ..a. He intends to See Gaius. - verses 13-14a
   ..b. He sends greetings. - verse 14b