Because of the way God created the world many things of value can be shared, but with totally different results. A shared reward is divided, a shared laugh is multiplied. A shared space subtracts the amount of room for you, a shared discovery adds to the joy.
There are similar created mysteries regarding debt. Some debts are big and others small, but a bigger debt might be less burdensome depending. What is owed? Who is it owned to? A small debt to a stingy lender is much worse than a great debt to a generous one. There are even some debts that compound joy as the debt increases.
In John Milton’s Paradise Lost he imagines many of the heavenly and hellish scenes before and during the fall of man. But before getting to Eve’s temptation and Adam’s sin he describes Satan’s decisive discontent in Satan’s words:
in a moment quit
The debt immense of endless gratitude, So burdensome, still paying, still to owe;
Forgetful what from him I still received,
And understood not that a grateful mind By owing owes not, but still pays, at once
Indebted and discharged; what burden then?
These lines describe true economics whether or not they describe Satan’s true thoughts. It is one of the reasons why Genesis 1:1 is so offensive because it means that there is a God we answer to, a God we are born without our choice already in debt to.
But this debt of gratitude we owe is a debt that increases our joy as we pay it and as the debt itself increases. It can’t be otherwise. God deserves more thanks the more He gives, and we are more joyful the more we are thankful. The more we owe and the more we pay, the more truly free we are.