1 Corinthians 8:7

8:7 But this knowledge is not shared by all. And some, by being accustomed to idols in former times, eat this food as an idol sacrifice, and their conscience, because it is weak, is defiled.

1 Corinthians 9:21

9:21 To those free from the law I became like one free from the law (though I am not free from God’s law but under the law of Christ) to gain those free from the law.