Third John 1:1–8 introduces the writer as “the elder,” which tradition says is the apostle John. It specifies that the letter is meant for Gaius, who is praised for his positive reputation. In particular, Gaius is applauded for caring for missionaries and other traveling Christians. This is especially important to John, so those preaching the truth aren’t dependent on the support of non-believers.
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“3 John 1:6” Bibleref.com
3 John 1:6-7
6 They have testified about your love before the assembly. You will do well to send them forward on their journey in a way worthy of God, 7 because for the sake of the Name they went out, taking nothing from the Gentiles.