3 John 1
The elder
See on 2Jo 1:1.
Gaius
The name occurs several times in the New Testament, as Act 19:29; Act 20:4; Rom 16:23; 1Co 1:14. The person addressed here cannot be identified.
The well-beloved
Rev., the beloved. In the Greek order the name comes first. Gaius the beloved.
In the truth (ἐν ἀληθείᾳ)
Rev., properly, omitting the article, in truth. See on 2Jo 1:4.

Beloved
Compare the plural, 1Jo 3:2, 1Jo 3:21; 1Jo 4:1, 1Jo 4:7, 1Jo 4:11.
I wish above all things (περὶ πάντων εὔχομαί)
Wrong. This sense of περί is contrary to New Testament usage. The preposition means concerning. So Rev. "I pray that in all things thou mayst prosper." εὔχομαι I pray or wish, occurs only here in John's writings, and not often elsewhere. See Act 26:29; Rom 9:3; Jam 5:16.
Mayst prosper (εὐοδοῦσθαι)
Lit., have a prosperous journey. From ἐν well, and ὁδός a way. In this original sense, Rom 1:10. The word occurs only three times in the New Testament. See 1Co 16:2.
Be in health (ὑγιαίνειν)
Used in the New Testament both in a physical and moral sense. The former is found only here and in Luke's Gospel. See Luk 5:31; Luk 7:10; Luk 15:27. Paul uses it of soundness in faith or doctrine. See 1Ti 1:10; 1Ti 6:3; 2Ti 1:13; Tit 2:2. Here of Gaius' bodily health, as is shown by soul in the next clause.
Soul (ψυχή)
See on Mar 12:30; see on Luk 1:46. The soul (ψυχή) is the principle of individuality, the seat of personal impressions. It has a side in contact with both the material and the spiritual element of humanity, and is thus the mediating organ between body and spirit. Its meaning, therefore, constantly rises above life or the living individual, and takes color from its relation to either the emotional or the spiritual side of life, from the fact of its being the seat of the feelings, desires, affections, aversions, and the bearer and manifester of the divine life-principle (πνεῦμα). Consequently ψυχή is often used in our sense of heart (Luk 1:46; Luk 2:35; Joh 10:24; Act 14:2); and the meanings of ψυχή soul and πνεῦμα spirit, occasionally approach each other very closely. Compare Joh 12:27, and Joh 11:33; Mat 11:29, and 1Co 16:18. Also both words in Luk 1:47. In this passage ψυχή soul, expresses the soul regarded as moral being designed for everlasting life. See Heb 6:19; Heb 10:39; Heb 13:17; 1Pe 2:11; 1Pe 4:19. John commonly uses the word to denote the principle of the natural life. See Joh 10:11, Joh 10:15; Joh 13:37; Joh 15:13; 1Jo 3:16; Rev 8:9; Rev 12:11; Rev 16:3.

Rejoiced greatly
See on 2Jo 1:4.
Brethren came (ἐρχομένων ἀδελφῶν)
Lit., coming. The present participle denotes coming from time to time, and not coming on a single occasion, which would require the aorist. On brethren, see on 1Jo 2:9.
Thou walkest in truth
See on 1Jo 1:8. for the phrase walk in, see on 2Jo 1:6. Thou is emphatic, suggesting a contrast with less faithful ones, as Diotrephes, 3Jo 1:9.

Joy (χαράν)
The texts vary; some reading χάριν grace or favor from God, on which see 2Jo 1:3. Note the Greek order: greater joy than this have I not.
My children (τὰ ἐμὰ τέκνα)
Lit., mine own children.
Walk (περιπατοῦντα)
Rev., rightly, walking. The participle expresses something habitual.

Thou doest faithfully (πιστὸν ποιεῖς)
Rev., thou doest a faithful work. A third interpretation is thou givest a pledge or guaranty, and a fourth, akin to this, thou makest sure. The Rev. is best. There is no parallel to justify the third and fourth.
Thou doest (ἐργάσῃ)
Or lit., according to the eymology, workest (ἔργον work). See on Jam 2:9. The distinction between this verb and others signifying to do, such as ποιεῖν, πράσσεῖν, δρᾶν, which last does not occur in the New Testament, is not sharply maintained in Attic Greek. In certain connections the difference between them is great, in others, it is hardly perceptible. On ποιεῖν and πράσσεῖν, see on Joh 3:21. ἐργάζομαι, like πράσσεῖν, contemplates the process rather than the end of action, carrying the ideas of continuity and repetition. It means to labor, to be active, to perform, with the idea of continued exertion, and therefore is used of servants, or of those who have an assigned business or office. See Mat 21:28; Mat 25:26; Luk 13:14; Joh 5:17; Joh 6:27; Joh 9:4; 1Th 2:9. For the phrase ἐργάσῃ εἰς thou doest toward (Rev.), see Mat 26:10.
And to strangers (καὶ εἰς τοὺς ξένους)
The best texts read, instead of εἰς τοὺς to the (strangers), τοῦτο, that; so that the sentence is, literally, "to them that are brethren, and that strangers." For the phrase and that, compare 1Co 6:6; Phi 1:28; Eph 2:8.

The Church (ἐκκλησίας)
See on Mat 16:18.
If thou bring forward on their journey (προπέμψας)
Lit., having sent forward. The aorist tense represents the act as accomplished. Compare Act 15:3; Tit 3:13. Rev., set forward.
After a godly sort (ἀξίως τοῦ θεοῦ)
Lit., worthily of God. So Rev. Compare 1Th 2:12; Col 1:10.
Thou shalt do well (καλῶς ποιήσεις)
For the phrase, see Act 10:33; Phi 4:14; Jam 2:8, Jam 2:19; 2Pe 1:19. Rev., renders the whole: whom thou wilt do well to set forward on their journey worthily of God.

For His Name's sake (ὑπὲρ τοῦ ὀνόματος)
His is supplied by the A.V. It is not in the text. Rev., correctly, for the sake of the Name. The Name (Jesus Christ) is used thus absolutely in Act 5:41; compare Jam 2:7. For a similar absolute use of the way, see on Act 4:2. See on 1Jo 1:7.
Taking nothing of (μηδὲν λαμβάνοντες ἀπὸ)
For the phrase taking of, or from, see on 1Jo 1:5.
The Gentiles (ἐθνικῶν)
This word occurs elsewhere only in the Gospel of Matthew. The more common word is ἔθνη, which is the reading of the Tex. Rec. here: ἐθνῶν. See on Luk 2:32.

Ought (ὀφείλομεν)
See on 1Jo 2:6.
To receive (ἀπολαμβάνειν)
The best texts read ὑπολαμβάνειν to support; i.e., to welcome with the provision of hospitality. Rev., welcome. The verb means, originally, to take underneath in order to raise. Hence, to support. Figuratively, to take upon the mind, to suppose, as Luk 7:43; Act 2:15 : to take up or follow in speech; hence to answer, as Luk 10:30.
Fellow-helpers to the truth (συνεργοὶ τῇ ἀληθείᾳ)
Lit., fellow-workers. The expression is explained in two ways: either fellow-workers with the teachers (τοιούτους such) in support of the truth; or fellow-workers with the truth. Adopt the latter, as Rev.

I wrote unto the Church
The best texts insert somewhat, which indicates that the apostle did not regard the communication as specially important.
Diotrephes (Διοτρέφης)
The name is from Δίος of Zeus (Jove), and τρέφω to nourish, and means Jove-nursed.
Who loveth to have the pre-eminence (ὁ φιλοπρωτεύων)
From the adjective φιλόπρωτος fond of being first. The word occurs here only.

10 Prating (φλυαρῶν)
From φλύω to bubble up or boil over. Hence of talk which is both fluent and empty. Compare the kindred adjective φλύαροι tattlers, 1Ti 5:13.
Them that would
Those who were disposed to receive the strangers.
Casteth them out
By excommunication, which, through his influence, he had power to bring about.

11 Follow (μιμοῦ)
More correctly, as Rev., imitate. Elsewhere only 2Th 3:7, 2Th 3:9; Heb 13:7. The kindred word μιμητής imitator, uniformly rendered follower in A.V., occurs 1Co 4:16; 1Co 11:1; Eph 5:1. Hence our word mimic; also pantomime. μῖμος means both an actor and a kind of prose drama, intended as a familiar representation of life and character, and without any distinct plot.
That which is evil - that which is good (τὸ κακὸν - τὸ ἀγαθόν)
Compare τὰ ἀγαθὰ good, τὰ φαῦλα evil, Joh 5:29.

12 Demetrius hath good report (Δημητρίῳ μεμαρτύρηται)
Lit., unto Demetrius witness hath been born. See Joh 3:26.

13 I had (εἶχον)
The imperfect tense: I was having, when I began to write.
Pen (καλάμου)
Lit., reed. See Mat 11:7. The staff or scepter placed in mockery in Jesus' hand, Mat 27:29. A measuring-reed, Rev 11:1.

14 Face to face
See on 2Jo 1:12.