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.

1 Korintus 15:2

15:2 and by which you are being saved, if you hold firmly to the message I preached to you – unless you believed in vain.

1 Korintus 11:23

11:23 For I received from the Lord what I also passed on to you, that the Lord Jesus on the night in which he was betrayed took bread,