13:8 Does this prohibit Christians buying anything on credit or borrowing money?
13:8 Does this prohibit Christians buying anything on credit or borrowing money?
No, money as such is not in view here. What Paul is saying continues on from his injunction to Christians in V1-7 to discharge all their obligations to civil authorities (CP V1-7).
Christians are to owe no man anything in the sense that they are to have no outstanding debts. All their debts must be kept up to date. The only outstanding debt Christians should owe is their debt of love to their fellow man. This is the only debt which they can never discharge (CP V8-10 with 1Cor 13:1-7 and Ga 5:13-14).
Neighbour in Ro 13 and Ga 5 means any other member of the human race, not only fellow Christians, but unbelievers also; even those who hate us (CP Mt 5:43-44;Lu 6:27-35; Jn 13:34-35; Ro 12:9-10, 14, 20-21; Eph 5:1-2; Php 1:9; Col 3:14; 1Th 4:9; 1Ti 2:15; He 6:10; 1Pe 1:22; 4:8; 1Jn 2:9-10; 3:23; 4:7-12, 20-21). Christian love seeks the welfare of all and works no ill to any. It is self-sacrificial, not self-seeking.
The Christian who loves his fellow man like this has fulfilled God's law in every respect. The commandments not to commit adultery, not to murder, not to steal, not to bear false witness, not to covet, and any other commandment, are all summed up in the commandment to love our neighbour as ourself (CP Ex20:13-17; Lev19:18; De 5:17-22).
See also comments on Jn 13:34-35; 1Cor 12:31; Ga 5:1-8, 5:13; 1Th 3:12; 1Jn 3:7, 3:15, 3:16-18, 3:19-22, 4:7-21; Rev 3:7-13 and author's study How Christians are to Love One Another in his book Foundational Truths of the Christian Faith.