1 Corinthians 9:19-27

For though I was free from all men, I brought myself under bondage to all, that I might gain the more. And to the Jews I became as a Jew, that I might gain Jews; to them that are under the law, as under the law, not being myself under the law, that I might gain them that are under the law; to them that are without law, as without law, not being without law to God, but under law to Christ, that I might gain them that are without law. To the weak I became weak, that I might gain the weak: I am become all things to all men, that I may by all means save some. And I do all things for the gospel’s sake, that I may be a joint partaker thereof. Know ye not that they that run in a race run all, but one receiveth the prize? Even so run; that ye may attain. And every man that striveth in the games exerciseth self-control in all things. Now they do it to receive a corruptible crown; but we an incorruptible. I therefore so run, as not uncertainly; so fight I, as not beating the air: but I buffet my body, and bring it into bondage: lest by any means, after that I have preached to others, I myself should be rejected.