1 Corinthians 9:20 (KJV)

What is my reward then? Verily that, when I preach the gospel, I may make the gospel of Christ without charge, that I abuse not my power in the gospel.

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.