'Debt' in the Bible

I have a debt to Greeks and to the nations outside; to the wise and to those who have no learning.

Now, the reward is credited to him who does works, not as of grace but as a debt.

So then, my brothers, we are in debt, not to the flesh to be living in the way of the flesh:

Be in debt for nothing, but to have love for one another: for he who has love for his neighbour has kept all the law.

Yes, it has been their good pleasure; and they are in their debt. For if the Gentiles have had a part in the things of the Spirit which were theirs, it is right for them, in the same way, to give them help in the things of the flesh.

Who for my life put their necks in danger; to whom not only I but all the churches of the Gentiles are in debt: