1 Corinthians 9:19-26

For though I am free from all men, I have made myself a slave to all, so that I may win more. To the Jews I became as a Jew, so that I might win Jews; to those who are under the Law, as under the Law though not being myself under the Law, so that I might win those who are under the Law; to those who are without law, as without law, though not being without the law of God but under the law of Christ, so that I might win those who are without law. To the weak I became weak, that I might win the weak; I have become all things to all men, so that I may by all means save some. I do all things for the sake of the gospel, so that I may become a fellow partaker of it. Do you not know that those who run in a race all run, but only one receives the prize? Run in such a way that you may win. Everyone who competes in the games exercises self-control in all things. They then do it to receive a perishable wreath, but we an imperishable. Therefore I run in such a way, as not without aim; I box in such a way, as not beating the air