The Law of Moses attempted to protect both borrower and lender. In Israel, borrowing and lending was not for big, commercial enterprises but rather to help the poor and needy who lacked everyday necessities.
In lending, the lender had the opportunity to help the poor in need. It was an act of love in which the lender actually lifted a burden by helping his fellow Israelite through a crisis, but was forbidden to charge usury. To relieve the burden of the poor, debts were released every seven years and property restored during the year of Jubilee.
In the New Testament, the practice of lending money at interest seemed to be accepted as normal business procedure. Although Jesus never condemned interest directly, in general, He was hard on the improper attitude toward riches and on the oppression of the poor, just as was the Old Testament.
The principle of making money from someone else's hardship is not really a godly way of doing business. But Deuteronomy 23:19-20 makes it clear that interest was never to be charged to a fellow Israelite. Today, that would be equivalent to never loaning money with interest to a fellow Christian.
Borrowing money is not condemned in scripture unless you interpret Romans 13:8 as speaking of borrowing. The bible makes it clear that borrowing is not God's best. Deuteronomy 28:12 lists never having to borrow as a blessing, while Deuteronomy 28:44 lists borrowing as a part of the curse of the law. Proverbs 22:7 says, "The rich ruleth over the poor, and the borrower is servant to the lender."