1 tn The author has already described Gaius as “dear friend” or “beloved” (τῷ ἀγαπητῷ, tw agaphtw) in v. 1; he will address Gaius in the same way in vv. 5 and 11 (᾿Αγαπητέ, Agaphte). This is a term of endearment and personal warmth, much as it is when used by the author as an address in 1 John 2:7.
2 tn BDAG 821 s.v. πιστός 1.b offers the translation “act loyally” for this context, a usage which is not common but does fit well here. Since the author is going to ask Gaius for additional help for these missionaries in the following verse, he begins here by commending Gaius for all that he has already done in this regard.
sn When the author tells Gaius “you demonstrate faithfulness by whatever you do” he is commending him for his faithful service to the traveling missionaries (the brothers). Gaius has assisted them, and they have now returned with a report of this to the author (3 John 3).
3 tn Grk “who” (a relative pronoun that continues the sentence begun in 3 John 5).
4 sn Which church does the author refer to here? The church where Gaius is, the church where the author is, a different local church where the “brothers” are, or the ‘universal’ church, the church at large? Since the suggestion in 3 John 3 is that the “brothers” have come and testified in the author’s church about what Gaius has done for them, it seems most likely that the “church” mentioned here is also the author’s church, where he is currently located. Other possibilities cannot be ruled out, but seem unnecessarily complicated.
5 sn Now the author, after commending Gaius for his faithful service to the traveling missionaries in the past (see 3 John 5), now requests additional assistance at the present time (send them on their way in a manner worthy of God). Apparently the missionaries are on their way to visit the area where Gaius’ church is located a second time. They had been there once already and had returned with a good report of how Gaius had assisted them. It is entirely possible that they themselves carry with them the present letter as a letter of introduction. Along these lines it has been suggested that Demetrius (see 3 John 12) is one of these traveling missionaries, perhaps the leader of the delegation, and the author is formally introducing him to Gaius, since when he was there the last time he was a stranger (v. 5) but Gaius assisted him anyway.