1 Corinthians 9:16-23
16If I proclaim the gospel, this gives me no ground for boasting, for an obligation is laid on me, and woe to me if I do not proclaim the gospel! 17For if I do this of my own will, I have a reward; but if not of my own will, I am entrusted with a commission. 18What then is my reward? Just this: that in my proclamation I may make the gospel free of charge, so as not to make full use of my rights in the gospel.
19 For though I am free with respect to all, I have made myself a slave to all, so that I might win more of them. 20To the Jews I became as a Jew, in order to win Jews. To those under the law I became as one under the law (though I myself am not under the law) so that I might win those under the law. 21To those outside the law I became as one outside the law (though I am not free from God’s law but am under Christ’s law) so that I might win those outside the law. 22To the weak I became weak, so that I might win the weak. I have become all things to all people, that I might by all means save some. 23I do it all for the sake of the gospel, so that I may share in its blessings.
Or in other words (the same text from The Message)...
16If I proclaim the Message, it's not to get something out of it for myself. I'm compelled to do it, and doomed if I don't! 17If this was my own idea of just another way to make a living, I'd expect some pay. But since it's not my idea but something solemnly entrusted to me, why would I expect to get paid? 18So am I getting anything out of it? Yes, as a matter of fact: the pleasure of proclaiming the Message at no cost to you. You don't even have to pay my expenses!
19Even though I am free of the demands and expectations of everyone, I have voluntarily become a servant to any and all in order to reach a wide range of people: 20religious, nonreligious, 21meticulous moralists, loose-living immoralists, 22the defeated, the demoralized--whoever. I didn't take on their way of life. I kept my bearings in Christ--but I entered their world and tried to experience things from their point of view. I've become just about every sort of servant there is in my attempts to lead those I meet into a God-saved life. 23I did all this because of the Message. I didn't just want to talk about it; I wanted to be in on it!