The above can be understood and explained using an analogy [given by] our great master, [the Alter Rebbe]:1 A person owes [a creditor] an immensely large sum of money and he does not have the means to repay his entire debt; only half. Being a man of integrity, [he finds himself in a quandary]. The fundamental honesty within his heart motivates him to pay his debt in its entirety, but he only has the wherewithal to pay half. Moreover, he is unable to pay even that half at one time, but rather bit by bit over many years. Now, if the creditor is a good person and agrees [to accommodate] the debtor, [the outcome will be positive]. [If he allows him] to pay [the debt] according to his means, i.e., just half the debt, and he even allows him to pay that half as he is able, i.e., spread out over many years, the debtor will try with all his power [not only to pay the half, but] to pay the entire debt. Since he is a man of integrity and, because of the fundamental honesty in his heart he truly desires to pay the entire debt but he does not have the means, the goodwill[and understanding] that the creditor shows him motivates him to try even harder until he is able to pay the entire debt or at least more than he originally thought he could. If, however, the creditor is harsh and insensitive and desires that the debtor pay everything that he owes and that he do so all at once, the debtor will become negligent [in paying the debt]; he will become confounded and he will not pay anything.

Similar concepts apply with regard to teshuvah. [In our Yom Kippur prayers,] we say: “You taught us, G‑d, our L‑rd, to confess before You… so that we be withheld from taking advantage.” A person who owes a debt and does not repay it at all is considered as one who takes advantage.[This also applies to spiritual debts.] Nevertheless, because “You taught us… to confess before You,” and “You forgive us,” we are motivated to pay [our spiritual] debts as well as we can, be it little by little. In this way, we will “be withheld from taking advantage.” For forgiveness generates strength and power, motivating us to try to pay all our [spiritual] debts through all sorts of endeavors.

Summary

[G‑d’s willingness to forgive] is described with the analogy of a kind creditor who is willing to adjust the terms of payment according to the capacity of the debtor. His goodwilland understanding motivates the debtor to strive greatly to pay the entire debt.