"It's not my fault" is a prevalent attitude in our culture. To avoid responsibility for their own actions, people blame others: "I wouldn't yell at my kids so much if my own mother had loved me more" or "I wouldn't speak unkindly about my boss if he showed me some respect." Resentment wells up until the victim is blind to everything except how his life is impacted by someone else's hurtful deeds. Then casting blame is easy. But God has a challenge for believers: Forgive those who wound you.
The Lord's Prayer mentions several of God's duties but lists only one for believers: to forgive debtors (Matt. 6:12). The metaphor of debt describes sin well. A wronged person often feels that the responsible party owes something, such as an apology or compensation. But by showing mercy to one who has sinned, you stamp his or her obligation to you "paid in full." Reparations and retribution are no longer required.
Sometimes our wounds are so deep that forgiveness does not come easily. Remember that Jesus bears the scars of others' sins, too, and His Holy Spirit enables believers to carry out this difficult task. While your debtor may have done nothing to deserve grace, choose to give it anyway, just as Jesus did for you.
When God forgives, He remembers wrongs no more (Jer. 31:34). This doesn't mean that transgressions magically ceases to have happened. Instead, the Lord refuses to use past wrongs as a reason to punish His people. He set the pattern of debt cancellation, and we are to follow His example (Matt 6:15).