Residing as we do in a monetary economy, we immediately and thoughtlessly translate biblical warnings and cautions about debt into financial terms. “Owe nothing to anyone” (Romans 13:8) means “don’t take out a thirty-year mortgage.”
It’s much more likely that Paul has social debts in mind. This might include indebtedness incurred through receiving loans and gifts of material goods, but it’s a broader category that involves services and favors of all sorts.
How can anyone avoid becoming obligated to another for favors received? To live is to be indebted. Here we can perhaps answer by glossing the notion that Jesus pays our debts:
This too refers not merely to commercial/financial debts but to social ones. And it means that we can expect Jesus to reward those who benefit us. Thus Paul acknowledges that the Philippians sent a gift to cover his needs (4:16), but expects God to reward them for their generosity (4:18-19). Paul doesn’t plan to repay the Philippians, and he nowhere acknowledges that he is in debt to them (as would be normal in his world). He encourages them to look to his Benefactor and Patron to supply their needs, as He supplied Paul’s needs.
We give, and expect a reward from God. We receive favors, and we trust the God who rewards to cover our debts by rewarding our benefactors. Thus we receive, yet we “owe nothing to anyone.”
The infinite God underwrites the whole economy of benefit and return, the entire economy of generosity.