The word "debt" is another word for "sin" but "debt" is a more correct translation of the original Greek text.
Actually, "debt" is a good word picture for what sin is! Sin is "missing the mark" or falling short of the standard.
God is a Holy and cannot abide sin. So, if I sin (when) I have fallen short of God's nature and His standard which puts me in a moral and spiritual debt to Him. And it is a debt I have no ability to ever pay. Each time I sin my level of debt deepens.
If you have ever been in debt financially you can begin to grasp the spiritual condition you find yourself in as a sinner. The more you sin the greater the debt, the deeper the hole you find yourself in and the more hopeless you feel. Every month as a new payment comes due you begin to panic realizing you cannot make the payment so you will fall deeper in debt and feel more hopeless.
A large and growing debt burden can crush you!
What do you do when you owe a debt you cannot pay while the debt continues to grow?
Do you cry?
Do you fret?
Do you resign yourself to a hopeless existence?
Do you become depressed?
Do you self-medicate with alcohol or drugs?
Well, when you owe a debt it either has to be paid or it has to be cancelled by the creditor. Right?
That brings us full circle in this thought.
We are debtors to God owing Him an ever-mounting moral debt that we have no hope of ever paying. Our only hope is for God to cancel the debt or release us from it!
God did both!
He paid your debt by sacrificing Jesus, His Son, on the cross of Calvary. Jesus, because He was sin-free (debt-free) was able to take the death penalty for you and the blood He shed on the cross atoned for your sins!
Jesus paid your debt and released you from the penalty of it!
All you have to do is believe it and receive it by trusting Jesus as your Savior!
What do you call a gift so great as that?