Jesus said “For if ye forgive men their trespasses, your heavenly Father will also forgive you: But if ye forgive not men their trespasses, neither will your Father forgive your trespasses.” Matt 6:14-15. That tells you how serious the subject of forgiveness is before God, and there is no exception when it comes to that. No matter what people do to you, as a Christian there is no room for unforgiveness from the message of Christ. This is what the natural man cannot do, but we are talking about a man that has been imparted by the grace of God.
The same way God forgave us, that is what He expects us to do to our fellow men. By human standard, many people deserve death because of the evil they have done. Take for instance, those who have killed people and committed so many atrocities, there is nothing they deserve than to perish in hell. But when such people repent, God will still forgive. That is why forgiveness is a mystery. Why will someone who has caused people tears still find a place in heaven. That is God. “Who is a God like unto thee, that pardoneth iniquity, and passeth by the transgression of the remnant of his heritage? he retaineth not his anger forever, because he delighteth in mercy.” Micah 7:18. So, if you are still living in sin despite the forgiving nature of God, then Satan must be after your life specially. I read of an attorney, who after meditating on several Scriptures, decided to cancel the debts of all his clients who had owed him money for more than 6 months. He drafted a letter explaining his decision and its Biblical basis and sent 17 debt canceling letters via certified mail. One by one, the letters were returned by the Postal Service, unsigned and undelivered. Sixteen of the seventeen letters came back to him because the clients refused to sign for and open the envelopes fearing that this attorney was suing them for their debts. We too owe a debt for our sin and God is willing to cancel it but many will not even open the letter that explains how. What are you waiting for? If God is ready to forgive, do not delay in repenting.