I have never heard a sermon on what I consider to be, perhaps, the greatest text on the subject; namely, III John 8. Which is as follows:
We, therefore, ought to take up (support) such men
so that we may be fellow-workers for the truth.
Gaius, along with unnamed others, had been thrown out of the church by Diotrophes (whom we assume was the pastor), who refused to share the limelight with visiting missionaries sent out by John. Gaius’ “sin” was that he gave money and supplies for these traveling missionaries to get safely to the next Christians’ home.
John is furious about what he did. And he tells Gaius to continue to support them in the future – no matter what the pastor might say or do. Indeed, he was soon coming with full apostolic authority to deal with (“remember”) the problem and the problem-maker!
In the midst of that discussion, John wrote the verse listed above. Playing on the Greek (in which he was writing), he says, Because these missionaries refused to “take” any support from the heathen to whom they preached (so as not to sully Christ’s name*), Gaius and other believers ought to “take up” such men. When one does so—supporting them in their work financially or otherwise – one becomes a “fellow-worker” for the truth. He is looked upon by God as if he too were out there on the mission field preaching the Word. What an incentive to give! Body
* There were man travelling sophists who were simply out to make money. They wanted not to be confused with them. They were not “selling” the gospel! The passage lends itself to a sermon about money-making in the church as well.
– Jay Adams