Whenever I hear about a restaurant or other establishment that refuses to serve police officers, I always want to ask, “Do you expect them to serve you?” After all, their service requires them to (at least potentially) put their very lives on the line for you. The worst that can happen to you by serving them is getting a rotten tip.
It just seems reasonable. When people put themselves out for you, you should be inclined to do the same for them. But as logical as that may seem to me in the abovementioned scenario, it was not quite so obvious for the Christians in Galatia. It had been the apostle Paul who had first brought the gospel to them, who had imparted the Holy Spirit to them, who had been left for dead in their streets at least once. (The “brand-marks of Jesus” in Galatians 6:17 were not figurative.)
This is the meaning of Galatians 6:6 — “The one who is taught the word is to share all good things with the one who teaches him.” It is not saying preachers deserve to be paid — although I am on the record as being in favor of that. The word “share” in the New American Standard Bible is related to the word for communion or fellowship — concepts that are almost exclusively spiritual, not carnal. Paul is saying, as he did throughout the book of Galatians, that he deserved their love and support — not those who opposed him and his teaching. Such ones were accursed of God (Galatians 1:8-9).
Given all Paul had done for them, it was reasonable for him to expect a little respect.