Romans 1:14

1:14 I am a debtor both to the Greeks and to the barbarians, both to the wise and to the foolish.

Romans 8:12

8:12 So then, brothers and sisters, we are under obligation, not to the flesh, to live according to the flesh

Romans 15:27

15:27 For they were pleased to do this, and indeed they are indebted to the Jerusalem saints. For if the Gentiles have shared in their spiritual things, they are obligated also to minister to them in material things.