Says Ambrose of the moneylenders: “If a person says: I have no money, they answer: Use mine, as if it were yours. Thus they draw him into the net. Then begins the torture. Interest is heaped upon interest, the poor man is forced to sell everything, and yet this is not enough to satisfy the creditor. He is thrown into prison, and often driven to suicide. Oh insatiable avarice, worthy of Satan, who most faithful portrait though art!”
To this, Gerhard Uhlhorn adds: “It must be understood that the teachers of the Church did not distinguish between fair and just interest and usury; that in their eyes all interest was unrighteous usury. They taught, that to a Christian the reception of any interest was sin. Proof was adduced from Luke vi, 34, 35 but especially from the Old Testament (Ex. xxii, 25; Deut xxiii, 19).”
And if you lend to those from whom you expect repayment, what credit is that to you? Even ‘sinners’ lend to ‘sinners,’ expecting to be repaid in full. But love your enemies, do good to them, and lend to them without expecting to get anything back. Then your reward will be great, and you will be sons of the Most High, because he is kind to the ungrateful and wicked. Luke 6:34-35
If you lend money to one of my people among you who is needy, do not be like a moneylender; charge him no interest. Exodus 22:25
Do not charge your brother interest, whether on money or food or anything else that may earn interest. Deuteronomy 23:19
Gerhard Uhlhorn, 1826-1901) Lutheran Theologian and Abbot of Loccum in Christian Charity in the Ancient Church (1883) 383.