For they went out on behalf of the Name, accepting nothing from the Gentiles.
I. John receives a good report of Gaius's faith and charity from the brethren. Gaius’s love for the brethren and hospitality to strangers proves his sincerity in the faith. II. Gaius is commended for his hospitality, a virtue extended to strangers and those of different churches. III. John expresses great joy in hearing of Gaius's walk in truth.
Commenting on 3 John 1:3-8
Because that for his name's sake they went forth,.... From Judea; either of their own accord to preach the Gospel, or being drove out by the unbelieving Jews, for professing the name of Christ; and be it which it will, there was good reason why they should be regarded, and especially since they did as follows, taking nothing of the Gentiles; even of those who...
Verse 7. Because that for his name's sake. The word "his" here refers to God; and the idea is, that they had undertaken this journey not on their own account, but in the cause of religion. They went forth. Or, they have gone forth--εξηλθον-- referring to the journey which they had then undertaken; not to the former one. Taking nothing of the Gentiles.