Charging Interest: The Sin We Turned into a Business Model

Why Lending Money at Interest Is Condemned by Scripture, the Saints, and the First Ecumenical Council—and Why That Matters Today

A young father sits at his kitchen table long after midnight. His wife and children are asleep. The bills are spread out before him. He has checked the numbers repeatedly, hoping he made a mistake somewhere. He has not. Rent is due in a few days. One child needs medicine. The family car has broken down. There is no money left.

He is not trying to become rich. He is not trying to expand a business. He is not trying to purchase luxuries. He is simply trying to survive. The next morning, embarrassed but out of options, he asks for help.

A wealthier man agrees to lend him the money. Relief washes over the father. His family will make it through the month after all. Yet there is a condition attached to the loan. The money must be repaid with interest. The lender will not merely recover what he gave. He will profit from another man’s emergency.

Most modern readers see nothing unusual about that arrangement. In fact, entire economies are built upon it. Banks do it. Credit card companies do it. Mortgage lenders do it. Governments do it. Millions of Christians participate in it without ever giving it a second thought. The practice now appears so normal that questioning it might seem absurd.

Yet if that same arrangement had been described to many of the great saints of Christian history, the reaction would have been startling. Again and again, Scripture condemns it. Again and again, the Church Fathers condemn it. Even the First Ecumenical Council condemns it. The uncomfortable truth is that what previous generations of Christians often called usury, modern society has transformed into one of its most important business models.

The discussion begins in Holy Scripture, with a question asked by King David. It is not a question about economics, banking, or commerce. It is a question about holiness.

“Lord, who may abide in Your tabernacle?
Who may dwell in Your holy hill?”

The answer that follows in Psalm 15 describes the character of a righteous man. He walks uprightly. He works righteousness. He speaks the truth in his heart. He keeps his promises. He honors those who fear the Lord. He refuses corruption. He loves his neighbor. Then, among these moral qualities, David includes a statement that many modern Christians skip right past:

“They do not charge interest on money they lend” (Psalm 15:5)

This verse becomes even more striking when we notice the company it keeps. Psalm 15 is not discussing technical financial regulations. It is simply discussing righteousness. The man permitted to dwell with God is a man who does not backbite with his tongue. He does not do evil to his neighbor. He does not take up a reproach against his friend. He does not take a bribe against the innocent. And he does not charge interest on loans.

That should stop us in our tracks. Scripture places usury in the same list as slander, bribery, and harming one’s neighbor. David does not treat lending money at interest as a morally neutral business practice. He treats it as part of the larger question of whether a man truly loves God and loves his neighbor.

Now return to the father sitting at the kitchen table.

Imagine him asking for help. Imagine another man seeing his desperation and deciding that the moment is an opportunity for profit. That is exactly the moral concern that repeatedly appears in the writings of the Early Church Fathers. They were not primarily worried about economics. They were worried about what happens to the human heart when another person’s hardship becomes a source of income.

The bishops who gathered at the First Ecumenical Council in A.D. 325 viewed the matter in exactly those terms. In Canon 17 they wrote:

“Forasmuch as many enrolled among the Clergy, following covetousness and lust of gain, have forgotten the divine Scripture, which says, He has not given his money upon usury, and in lending money ask the hundredth of the sum [as monthly interest], the holy and great Synod thinks it just that if after this decree any one be found to receive usury, whether he accomplish it by secret transaction or otherwise, as by demanding the whole and one half, or by using any other contrivance whatever for filthy lucre’s sake, he shall be deposed and his name stricken from the list.”

Notice the language used by the council. The bishops do not speak of entrepreneurship, investment, or economic growth. Instead they speak of “covetousness,” “lust of gain,” and “filthy lucre.” They saw a spiritual problem beneath the financial transaction. The lender was not simply recovering what he had given. He was seeking profit from another person’s need.

And they weren’t only condemning exorbitant rates. In canon 17 above, the example given is one percent per month, which is an annual interest rate of 12%.

Imagine reading that canon aloud in the lobby of a modern bank. Imagine reading it to the executives of a credit card company. Imagine explaining to the bishops of Nicaea that entire corporations now exist for the purpose of lending money at interest. The contrast is astonishing. A practice they associated with greed has become one of the pillars of the modern economy.

St. Leo the Great speaks with the same concern:

“The evil of usury must be shunned, and the profit that lacks all human kindness must be avoided. The means for unjust and grievous gain is increased, but the essence of the soul is worn down, since usury in money is the ruin of the soul. The holy prophet David showed what God thinks about the people of this kind when he says, “Lord, who will dwell in your tent, or who will rest on your holy mountain?” Those are taught by the reply of the divine voice, and those know that they have a part in eternal rest if, among the other rules of a holy life, “they do not give their own money at usury.” They are shown to be strangers to the “tent” of God and foreign to his “holy mountain” if they seize a deceitful profit for their money by usury, and, while they want to be rich through another’s loss, they are worthy to be punished by eternal penury.”

Leo’s words strike at the very heart of the issue. He describes people who “want to be rich through another’s loss.” That phrase summarizes the entire traditional Christian critique of usury. The lender gains because another person is struggling. His prosperity is connected to another man’s burden.

The sixth-century monk Cassiodorus makes the same point in a simpler way. Commenting on Psalm 15, he says:

“We are absolutely forbidden to put [money] out to usury, because it is the vice of greed to seek to demand what you know you have not lent.”

His observation is difficult to escape. If a man lends one hundred dollars and later demands one hundred and ten, the extra ten dollars were never lent in the first place. The lender seeks ownership of something he never gave away. Cassiodorus sees that desire not as generosity, not as mercy, and not as justice, but as greed.

Nor did the Fathers believe that the effects of usury were limited to individual transactions. St. Ambrose of Milan observed:

“Nations have often failed because of usury, and this has been the cause of public calamity.”

The statement may sound dramatic, but St. Ambrose was looking beyond individual loans. Debt can burden families. Debt can burden communities. Debt can burden entire nations. A society that normalizes profiting from debt eventually finds itself surrounded by debt. The consequences spread far beyond the original lender and borrower.

Yet perhaps the strongest condemnation comes from St. Basil the Great. Basil refuses to discuss usury as an abstract economic principle. Instead, he directs our attention back to people. He wants us to see the hungry. He wants us to see the poor. He wants us to see the frightened father who is desperately trying to provide for his family.

Then St. Basil asks us to consider what the lender is actually profiting from:

“This interest, which you take, is full of extreme inhumanity. You make profit from misfortune, you collect money from tears, you strangle the naked, you beat the famished; nowhere is there mercy, no thought of relationship with the sufferer; and you call the profits from these things humane!”

The imagery is deliberately uncomfortable. Basil does not allow the lender to hide behind financial language. He strips away the spreadsheets, contracts, and calculations and asks what is really happening. The lender profits from misfortune. He profits from tears. He profits from desperation. He profits because someone else is in trouble.

St. Basil continues:

“Woe to you who say that the bitter is sweet and the sweet bitter, and who call inhumanity by the name of humanity. . . . People do not gather grapes from thorns or figs from thistles, or humanity from interest. Every bad tree bears bad fruit.”

Notice what Basil is attacking. He is attacking the habit of renaming things. People take something harsh and give it a respectable title. They take something rooted in greed and call it prudence. They take something rooted in exploitation and call it business. Basil insists that changing the label does not change the reality.

He then offers a radically different vision of how Christians should treat those in need:

“Give the money, since it is lying idle, without weighing it down with additional charges, and it will be good for both of you. There will be for you the assurance of its safety because of his custody; for him receiving it, the advantage from its use. And, if you are seeking additional payment, be satisfied with that from the Lord. He himself will pay the interest for the poor. Expect kindly acts from him who is truly kind.”

Basil’s solution is not indifference. He does not tell Christians to ignore the poor, to refuse loans, or to turn away from people in distress. Quite the opposite. He tells them to help, to lend, and to trust God rather than extracting profit from the suffering of others.

That is why he concludes with these words:

“It is wicked lending for both, for the giver and for the receiver, bringing loss to the one in money and to the other in soul.… It is not evident for whom you collect. It is indeed apparent who he is who weeps because of the interest, but it is doubtful who he is who is to enjoy the abundance that comes from it. In fact, it is uncertain whether you will not leave to others the gift of wealth, but the evil of injustice you have treasured up for yourself. “And from him who would borrow of you, do not turn away,” and do not give your money at interest, in order that, having been taught what is good from the Old and the New Testament, you may depart to the Lord with good hope, receiving there the interest from your good deeds, in Christ Jesus our Lord, to whom be glory and power forever. Amen.”

The father from the opening story still exists. He exists in every generation. He exists wherever families struggle, wherever unexpected expenses arise, wherever people find themselves trapped between desperation and debt. The question raised by Psalm 15, by St. Leo, by St. Cassiodorus, by St. Ambrose, by St. Basil, and by the bishops of Nicaea is not merely an economic question. It is a moral question.

When another person falls into hardship, do we see an opportunity for mercy or an opportunity for profit?

That question explains why King David categorized usury alongside slander, bribery, and doing evil to one’s neighbor. It explains why the Early Church Fathers spoke so forcefully. It explains why the First Ecumenical Council condemned the practice. They believed that lending money at interest was not simply a financial arrangement. They believed it revealed something about the condition of the human heart.

Modern Christians may debate how these teachings apply to contemporary financial systems. They may argue about banking, inflation, investment, or commercial lending. Those discussions are important. What cannot honestly be denied, however, is the witness of the sources themselves. Holy Scripture condemns usury. The saints condemn usury. The First Ecumenical Council condemns usury. Lending money at interest is a serious sin.

That reality should at least force us to ask a question that modern society rarely asks: if charging interest was once regarded as a serious sin, how did it become one of the foundations of modern economic life? More importantly, have we become so accustomed to profiting from debt that we no longer recognize why previous generations of Christians found the practice troubling?

King David’s question still stands:

“Lord, who may abide in Your tabernacle?
Who may dwell in Your holy hill?”

And among the answers he gives is one that remains every bit as challenging today as it was three thousand years ago:

“They do not charge interest on money they lend” (Psalm 15:5).