1 Corinthians 9:20

9:20 To the Jews I became like a Jew to gain the Jews. To those under the law I became like one under the law (though I myself am not under the law) to gain those under the law.

1 Corinthians 15:28

15:28 And when all things are subjected to him, then the Son himself will be subjected to the one who subjected everything to him, so that God may be all in all.