1 Korintus 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 Korintus 15:10

15:10 But by the grace of God I am what I am, and his grace to me has not been in vain. In fact, I worked harder than all of them – yet not I, but the grace of God with me.