Interest Never Sleeps: A Meditation on Time and Money

Somewhere on your street tonight a porch light will burn until morning, and nobody will lose a minute of rest over it, because the cost of a forgotten bulb is a rounding error. But suppose the bulb billed differently. Suppose it charged not a flat pittance but a percentage, and the percentage fed on itself, so that every hour it burned made the next hour dearer. You would not sleep so soundly with that light on. You would get up in your socks and switch it off. That, stripped of its paperwork, is what a debt is. It is a meter that runs while you are doing something else: while you work, while you worship, while you sing at a wedding, and, most instructively of all, while you sleep.

"The rich ruleth over the poor, and the borrower is servant to the lender."

Proverbs 22:7 (KJV)

I want to spend a little while with that verse, because it is one of those Proverbs we nod at and hurry past, and it deserves better. Notice what it does not say. It does not say the borrower is foolish, or wicked, or beyond hope. It says something more precise and more uncomfortable: the borrower is a servant. Servanthood, at bottom, is a question of whose schedule you keep, and a debt is a claim on your schedule. It is a mortgage on your mornings. Before this meditation is finished I hope to persuade you of two things. First, that interest is best understood not as a price on money but as a price on time. Second, that the same tireless arithmetic which grinds against a borrower will, once you turn it around, grind just as patiently in your favor. The numbers involved are real, and we will look at them squarely, because reverence for God has never yet required fuzziness about mathematics.

A Definition, Held Up to the Light

Begin with the definition, the way you might pick up an unfamiliar tool from a neighbor's bench and turn it over before trusting your thumb to it. Interest, we say, is the cost of borrowing money. True enough, as far as it goes. But tip the definition on its side and look underneath. The lender is not really selling you money; money is only the wrapping paper. What he sells you is time. He hands over the harvest of hours he has already worked, and in exchange you pledge him hours you have not yet lived. A loan is a trade between your past and your future, brokered in the present, and interest is the broker's commission. Seen that way, the old Proverb stops being a scolding and becomes a simple description. Of course the borrower is a servant. His future hours are spoken for before he arrives in them. Monday morning comes, and a slice of Monday already belongs to someone else, and so does a slice of every Monday after it until the account is settled.

Compound interest adds one further turn of the screw, and it is the turn that matters. Simple interest charges rent on the original sum and is content. Compound interest charges rent on the rent. Each month's unpaid interest is quietly folded into the principal, and the next month's charge is figured on the new, slightly larger figure, and so on without any natural stopping place. Nothing dramatic happens on any particular day, which is precisely the genius and the danger of the arrangement. A kettle at least announces itself with a whistle. A compounding balance never whistles. It simply grows, at three in the afternoon and at three in the morning, on ordinary Tuesdays and on Easter Sunday, with the calm indifference of arithmetic.

Put real numbers on the abstraction and it grows teeth. The Federal Reserve's consumer credit figures show Americans carrying roughly $1.3 trillion in revolving debt, most of it on credit cards, and the average rate on card accounts actually being charged interest has been running near 23 percent, a level the Consumer Financial Protection Bureau has described as historically high. So consider one unremarkable household with an $8,000 balance at 24 percent APR, a rate thousands of statements will show this month. That balance costs $160 in its first thirty days. It costs about $5.26 every single day, of which roughly a dollar seventy-five accrues during a decent night's sleep. Nobody feels it happening. That is rather the point.

The Worker Who Never Clocks Out

The Psalmist, wanting to steady pilgrims on a dangerous road, reached for the most reassuring fact he knew: "Behold, He that keepeth Israel shall neither slumber nor sleep" (Psalm 121:4, KJV). Sleeplessness, in Scripture, is a Divine attribute. God alone keeps a perfect, unbroken watch. Everything else in creation tires: shepherds doze at their fires, sentries blink on the wall, and the most determined borrower must eventually put his head on a pillow.

Now here is the odd and slightly chilling thing about compound interest: it mimics that attribute. It is only arithmetic, of course. There is no malice in a percentage, any more than there is malice in frost. But it shares with frost the habit of working the night shift. It does not slumber. It takes no holidays, asks for no encouragement, and never once gets discouraged. When people say a debt is hanging over them, they are reporting something quite exact about its geometry: it is above them, and it is always on duty.

But notice, for this is the hinge of the whole meditation, that the arithmetic has no loyalties. Compounding does not care whose side it is on. The very same relentlessness that swells a balance against you will swell a balance for you, provided the balance is in your name and to your credit. A dollar is a servant that works around the clock for whoever holds its papers. Watch what a single thousand dollars does over ten years depending on which side of the ledger it sits, whether as an unpaid card balance, as ordinary invested savings, or in a high-yield savings account near the best rates the FDIC tracks.

The debt line embarrasses the other two, and that embarrassment is the lesson. When the rate running against you is 24 percent and the best rate running for you is 4 or 7, there is no clever route around the debt. You do not outswim that kind of current with beautiful form; you get out of the river. Our Lord stated the underlying principle in words that have never needed improving:

"No man can serve two masters: for either he will hate the one, and love the other; or else he will hold to the one, and despise the other. Ye cannot serve God and mammon." (Matthew 6:24, KJV)

Money, in other words, will be either your servant or your master; it has no gift for equality. A high-interest debt is money in its most masterful mood, issuing standing orders around the clock. And a Christian has a particular reason to resent those orders, namely that his hours were already pledged elsewhere. The time that interest quietly annexes, the overtime worked to feed it, the generosity postponed because of it: all of that was meant for the service of God and neighbor. The deepest problem with being the lender's servant is not that it is unpleasant. It is that you were engaged, at unspeakable expense, by Someone else.

Counting the Cost Before the Tower

"For which of you, intending to build a tower, sitteth not down first, and counteth the cost, whether he have sufficient to finish it?" (Luke 14:28, KJV)

Jesus asked that question about the cost of following Him, and He chose the illustration with a builder's realism. Everyone in that crowd had walked past a half-finished tower, and everyone knew what the bare scaffolding said about the man who began it. The habit of mind He appeals to, sit down first, count, then decide, is exactly the habit that modern borrowing is engineered to bypass. Nobody sits down at the point of sale. The card is tapped standing up, in about a second and a half, and the counting is deferred indefinitely.

So let us do the sitting down now, retroactively, on behalf of that $8,000 balance. The decisive number turns out to be neither the balance nor even the rate, but the monthly payment, because the payment determines how long you and the meter remain in business together. Here is the identical debt at four different payments, with nothing else changed.

Read the first row slowly, because whole years of somebody's life are folded into it. At $200 a month, a payment that feels perfectly respectable, the debt takes eighty-one months to die, very nearly seven years, and the interest paid along the way exceeds the amount originally borrowed. You buy the thing twice and receive it once. And the first row is no accident of my choosing. Card minimum payments are commonly set near 1 percent of the balance plus that month's interest, which is to say, set so that the garden wall is repaired just slightly faster than the frost cracks it, and not one brick faster. The arrangement is lawful and fully disclosed. But it is designed, and a sensible person treats a designed current the way a swimmer treats an undertow: with respect, and with a firm plan for leaving it.

Then read the last row. The difference between $200 and $600 a month is not a different moral universe or a different income bracket; for many households it is one car payment's worth of intensity, found by selling, pausing, and pruning. Yet it converts eighty-one months of servitude into sixteen, and it returns about $6,855 to your own table that would otherwise have been paid out as rent on time. There are few places in ordinary life where resolve is exchanged for money at so favorable a rate.

Change One Number and Watch the Clock

Abstract resolve is cheap; a lever you can actually pull is precious. In the whole machinery of a debt there is exactly one number the borrower controls completely, and it is the payment. The balance is history. The rate belongs to the lender. The payment is yours. Try the lever yourself below: enter your own balance and rate, then move the payment up by fifty dollars, and then by a hundred, and watch what happens to the months.

Notice how the months respond. They do not fall politely, one for one; they fall in ranks, several at a time. That is compounding running in reverse, the frost melting faster than it can form. Every extra dollar strikes the principal directly, and every dollar of principal removed stops earning interest against you for the entire remaining life of the debt, which is why the arithmetic rewards earliness so extravagantly. An extra hundred dollars a month is not really a purchase of groceries forgone. It is a purchase of time. It is the earlier train home. And unlike nearly everything else money can buy, this purchase cannot disappoint you: a 24 percent charge avoided is a 24 percent return earned, guaranteed, untaxed, and perfectly indifferent to the stock market's moods.

The Way Out Is Also Made of Time

How, then, does anyone actually get out? Almost never by windfall, and never by mood. Moods are the wrong shape for this work. A debt is a schedule, and only another schedule can defeat it. It is telling that when Scripture wants to teach financial diligence, it points not to a genius or a king but to the least dramatic worker in the field:

"Go to the ant, thou sluggard; consider her ways, and be wise: Which having no guide, overseer, or ruler, Provideth her meat in the summer, and gathereth her food in the harvest." (Proverbs 6:6-8, KJV)

The ant's genius is not intensity but continuity. She has no supervisor and no deadline, and she does a small right thing in every hour available for it, and by autumn the arithmetic of her patience is unanswerable. Against an adversary that never sleeps, that is the only style of fighting that wins: not heroics, but hours. Here is the ant's method translated for a household with card balances.

Two honest footnotes belong to that plan. First, the avalanche order is the cheapest path in dollars, but the snowball order, smallest balance first, produces quicker finished accounts, and some households need the encouragement more than they need the dollars. Choose whichever order you will still be obeying in month fourteen, for continuity is the entire secret. Second, the plan assumes you intend to repay everything you owe, and that intention is not mere strategy. "The wicked borroweth, and payeth not again: but the righteous sheweth mercy, and giveth" (Psalm 37:21, KJV). Repayment is a matter of righteousness before it is ever a matter of credit scoring. Paul gathers the whole subject into a single line: "Owe no man any thing, but to love one another: for he that loveth another hath fulfilled the law" (Romans 13:8, KJV). He is not issuing a banking regulation; he is describing the direction a Christian's obligations ought to flow. Debts of money are to be discharged and closed, precisely so that the one permanent debt, the debt of love, can be paid gladly and forever.

Numbering Our Days

Moses, the one Psalmist who watched an entire generation run out of time in the wilderness, prayed: "So teach us to number our days, that we may apply our hearts unto wisdom" (Psalm 90:12, KJV). It is worth observing that numbering days is exactly what a lender does. The amortization schedule folded into your statement is a numbered account of your days, eighty-one of your months, drawn up by someone else and mailed to you monthly. The invitation of this meditation is simply to take the numbering back: to sit down, as the tower builder should have done, and count your own cost, on your own paper, before God rather than before a credit bureau.

Let me be plain about what is not being promised here, because it matters. Getting out of debt will not oblige God to make you rich. Scripture never trades on that arithmetic, and neither should we. Faithful people lose jobs, face long illnesses, and bury their dead, and their faith was never a coupon against hardship. The reward of a paid-off balance is not that Heaven then owes a dividend. The reward is the freedom itself: the Monday no one else has claimed, the $160 a month that stays home, the widened room for generosity, the sleep that is only sleep and not the quiet accrual of somebody else's rent.

So go back, in your mind, to that porch light. The bulb that bills by the compounding percentage is burning right now over a great many doors, including, perhaps, yours, and the meter does not observe the Sabbath. But the door it hangs over is still your door. You can get up in your socks tonight, take one written page, one honest count, one deliberately larger payment, and begin switching it off. Interest never sleeps. Neither does the God who keeps you, and He, not the meter, has the final claim on your days.