Matthew 18:21-35, ESV:
21 Then Peter came up and said to him, "Lord, how often will my brother sin against me, and I forgive him? As many as seven times?"
22 Jesus said to him, "I do not say to you seven times, but seventy times seven (NIV, seventy-seven times).
23 "Therefore the kingdom of heaven may be compared to a king who wished to settle accounts with his servants.
24 When he began to settle, one was brought to him who owed him ten thousand talents.
25 And since he could not pay, his master ordered him to be sold, with his wife and children and all that he had, and payment to be made.
26 So the servant fell on his knees, imploring him, 'Have patience with me, and I will pay you everything.'
27 And out of pity for him, the master of that servant released him and forgave him the debt.
28 But when that same servant went out, he found one of his fellow servants who owed him a hundred denarii, and seizing him, he began to choke him, saying, 'Pay what you owe.'
29 So his fellow servant fell down and pleaded with him, 'Have patience with me, and I will pay you.'
30 He refused and went and put him in prison until he should pay the debt.
31 When his fellow servants saw what had taken place, they were greatly distressed, and they went and reported to their master all that had taken place.
32 Then his master summoned him and said to him, 'You wicked servant! I forgave you all that debt because you pleaded with me.
33 And should not you have had mercy on your fellow servant, as I had mercy on you?'
34 And in anger his master delivered him to the jailers (original=basanistais, "torturers") until he should pay all his debt.
35 So also my heavenly Father will do to every one of you, if you do not forgive your brother from your heart."
When God forgives us, He "removes our transgressions from us, as far as the east is from the west."
He does this to remove evil from our lives. When we receive forgiveness, we are expected to forgive in like fashion--freely, completely, with grace rather than grudging, and thus remove evil from our lives in another way. When I forgive someone, I eliminate his control over me, and I remove the leverage Satan has in my soul. I no longer have to think about how I'll "get even." I no longer fret about the injustice. I'm not angry about the past. I can let the evil go, and move on to the new life God has promised me.There is almost nothing more important in the Christian life than forgiveness. Failure to forgive ruins our present and our future, and the past becomes the present as we stew over it.
As I read this text, and go over my own life-history, I see many problems caused by failure to forgive. Some, of course, were my own problems (yes, I have sometimes failed at this), and others I observed in people I knew.
The text above discusses the realities of forgiveness, and the problems we face if we do not forgive.
Peter asked, "How often?" Jesus said, "Don't stop."
Then Jesus told a story about a king and a subject. The king forgives the subject. The subject goes out after receiving forgiveness, and refuses to forgive his fellow-subject.
Then the king imprisons the first subject, delivering him to the torturers until he pays up.
This last statement brings up a very real point, and enforces what I've observed over the years. When you refuse to forgive, something happens to YOU--the failure twists you, alters your perspective, makes you full of hate and evil. Sometimes this evil lives in your soul quietly, with nobody but you knowing your rage and desire to destroy. Sometimes it breaks out into the taking of revenge, and strangely enough, often makes you just like the person whom you need to forgive.
What Jesus tells us about how the evil in our hearts imprisons and tortures us is true. I've seen it too many times to count, and I've felt it.
So if there is someone in your life whom you need to forgive, do it. NOW. Otherwise you, too, will live your life out with mental torment and rage. It will eat you up and destroy you. Don't let that happen. Forgive. Set yourself free from those who've wronged you, and walk away. You can do it. Do it right now.
You may have to forgive over and over. Do it. When the person comes back into your mind, forgive them. Pray for them.
This, by the way, opens the door for GOD to deal with them as He sees fit. He knows how to do that, and what they need.
And never forget the story of the debtor who owed so much, whom the Lord freely forgave. That's you. Now go and do likewise.