1 Corinthians 3:13

3:13 each builder’s work will be plainly seen, for the Day will make it clear, because it will be revealed by fire. And the fire will test what kind of work each has done.

1 Corinthians 9:18

9:18 What then is my reward? That when I preach the gospel I may offer the gospel free of charge, and so not make full use of my rights in the gospel.