1 Corinthians 9:18 (KJV)

Do ye not know that they which minister about holy things live of the things of the temple? and they which wait at the altar are partakers with the altar?

Even so hath the Lord ordained that they which preach the gospel should live of the gospel.

But I have used none of these things: neither have I written these things, that it should be so done unto me: for it were better for me to die, than that any man should make my glorying void.

For though I preach the gospel, I have nothing to glory of: for necessity is laid upon me; yea, woe is unto me, if I preach not the gospel!

For if I do this thing willingly, I have a reward: but if against my will, a dispensation of the gospel is committed unto me.

For though I be free from all men, yet have I made myself servant unto all, that I might gain the more.

And unto the Jews I became as a Jew, that I might gain the Jews; to them that are under the law, as under the law, that I might gain them that are under the law;

To them that are without law, as without law, (being not without law to God, but under the law to Christ,) that I might gain them that are without law.

To the weak became I as weak, that I might gain the weak: I am made all things to all men, that I might by all means save some.

And this I do for the gospel's sake, that I might be partaker thereof with you.