1 Corinthians 9:14-18

14Even so hath the Lord ordained that they who preach the gospel should live by the gospel.

15But I have used none of these things: neither have I written these things, that it should be so done to me: for it were better for me to die, than that any man should make my glorying void. 16For though I preach the gospel, I have nothing to boast of: for necessity is laid upon me; and, woe is to me, if I preach not the gospel! 17For if I do this thing willingly, I have a reward: but if against my will, a dispensation of the gospel is committed to me. 18What is my reward then? Verily that, when I preach the gospel, I may make the gospel of Christ without charge, that I may not abuse my right in the gospel.