“I, wisdom, dwell together with prudence;
I possess knowledge and discretion. 
“How have you ridden motorcycles for forty years and never been hurt when seven of my friends have been badly injured or killed on them?” The more I thought about my young friend’s question, the more safety precautions I listed. But then I realized it boils down to one thing, and that one thing is the secret to everything. It’s the secret to motorcycle safety and economic security. It’s the secret to physical health and psychological wellbeing. It’s the secret to a successful life, and it is baked into the universe as surely as gravity.
The secret is margin.
The old word for it is prudence, and its spiritual roots go back to the Garden of Eden when our first parents decided they could do life without God in their hubris. “Cursed is the ground for your sake,” said God. “In pain, you shall eat of it all the days of your life. Thorns and thistles it will grow for you. By the sweat of your face, you shall eat bread till you return to the ground.” The need for margin was born that day—the cosmic Murphy’s Law—and whoever observes it reaps the benefits.
An airline pilot and flight instructor who was retiring after fifty accident-free years (we never hear about those guys, do we?) boiled it all down to one simple principle: Always fly with the idea that if anything can go wrong, it will and work hard to prepare for it. For example, most general aviation accidents result from fuel exhaustion. The veteran’s advice? Never assume the gages are correct. Always know exactly how much you put in before you launch and exactly how many gallons per hour that ship burns. Then land and refuel when you think you have one hour of flying time remaining. Simple right? Impose a one-hour fuel margin and NEVER break it. That’s prudence. That’s margin.
It is the same with money. We live in a world of economic hazards. Anything can go wrong and usually will at the worst possible moment. A tornado can blow your house down or flood it. A pandemic can destroy your job. Yet few operate with any self-imposed financial margins. We fly along on credit with little to no reserve, assuming that all will be well. Until the bottom drops out, the sky closes in, and our economic engines start to sputter. Safe landings are hard to come by in those situations.
But the biblical principle (see Proverbs 6:6-11) is simple: Work hard, spend less than you earn, set aside funds for future contingencies, and do it consistently, year after year. Then the poverty tsunami cannot catch you, nor the scarcity bandit overpower you.
Margin. Prudence. Marriages need it, churches need it, and people need it. With it, we have enough to make it through the inevitable tough times brought on by the fall. Without it, we fall apart.