When I was around 18 years old, I had an uncle that was an alcoholic. His girlfriend called me and asked if I would go over to his house because he was planning on relapsing after having a years sobriety and she could not get there because she was out of town.
Stupidly I went there by myself to try to stop him. I talked to him and pleaded with him and grabbed his car keys, but he was 35 and alot stronger than me. He overpowered me and got his keys and left the house. That night he got into a car accident and broke both of his wrists. I did not speak to him for 12 years.
Fast forward to when I was 35 and not so innocent and not so self-righteous. He was dying of esophageal cancer. I wrote him a letter telling him that I forgave him for everything and that I was very sorry he was sick. I did not hear back from him before he died. I have always regretted the fact that I did not forgive him sooner, and the fact that I'm sure he suffered far worse for that stupid car accident than I ever did.
Since becoming a Christian, I have learned that unforgiveness is a gateway to demons. It is documented in the following verses:
Then came Peter to him, and said, Lord, how oft shall my brother sin against me, and I forgive him? till seven times? Jesus saith unto him, I say not unto thee, Until seven times: but, Until seventy times seven.
Therefore is the kingdom of heaven likened unto a certain king, which would take account of his servants. And when he had begun to reckon, one was brought unto him, which owed him ten thousand talents. But forasmuch as he had not to pay, his lord commanded him to be sold, and his wife, and children, and all that he had, and payment to be made. The servant therefore fell down, and worshipped him, saying, Lord, have patience with me, and I will pay thee all. Then the lord of that servant was moved with compassion, and loosed him, and forgave him the debt.
But the same servant went out, and found one of his fellowservants, which owed him an hundred pence: and he laid hands on him, and took [him] by the throat, saying, Pay me that thou owest. And his fellowservant fell down at his feet, and besought him, saying, Have patience with me, and I will pay thee all. And he would not: but went and cast him into prison, till he should pay the debt. So when his fellowservants saw what was done, they were very sorry, and came and told unto their lord all that was done.
Then his lord, after that he had called him, said unto him, O thou wicked servant, I forgave thee all that debt, because thou desiredst me: Shouldest not thou also have had compassion on thy fellowservant, even as I had pity on thee? And his lord was wroth, and delivered him to the tormentors, till he should pay all that was due unto him. So likewise shall my heavenly Father do also unto you, if ye from your hearts forgive not every one his brother their trespasses. Matt 18:21-35
The tormentors in that verse are demons. Unforgiveness opens you up to demons who will cause that to be a weight on your life that will just get heavier and heavier. If you can't seem to forgive people in your past or your life, pray to your Father to help you to forgive them, because forgiveness is always the Lord's will.
Dear Heavenly Father, help me to be forgiving to anyone who has trespassed against me (whether real or imagined.) Thank you Lord for the many many things you have forgiven me in my life. In the name of Jesus Christ. Amen.