1 Corinthians 9:19-23

For though I was free from all, I brought myself under bondage to all, that I might gain the more. To the Jews I became as a Jew, that I might gain Jews; to those who are under the law, as under the law, that I might gain those who are under the law; to those who are without law, as without law (not being without law towards God, but under law towards Messiah), that I might win those who are without law. To the weak I became as weak, that I might gain the weak. I have become all things to all men, that I may by all means save some. Now I do this for the sake of the Good News, that I may be a joint partaker of it.