1 Corinthians 9:21-23

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. And this I do for the gospel's sake, that I might be partaker thereof with you.