Therefore, as the elect of God, holy and beloved, put on tender mercies, kindness, humility, meekness, long-suffering; bearing with one another, and forgiving one another, if anyone has a complaint against another; even as Christ forgave you, so you also must do.
Forgiveness is one of the hardest things for we humans do to give. As the scripture above states "as the elect of God" we must be able to forgive others who have wronged us. Afterall, we've wronged others as well. We must seek forgiveness also.
This next piece is a heart wrenching convicting piece that strips us of our right to hold a grudge:
In his book, Being the Body, Chuck Colson recalls a supernatural act of forgiveness. Rusty had brutally killed several people and sat on death row. While awaiting his fate, Rusty became a Christian and immediately began to grow in Christ. He sent letters to the families of his victims, apologizing for his actions and asking their forgiveness. About a year later, one of the families arranged to visit with him. You can imagine the tension as Rusty faced the family of one of the victims. And you can imagine Rusty's surprise when the father said, "For years I hated you. But when I came to understand that Christ has forgiven me of all my sins, I knew I had no choice but to forgive you. We're here today to let you know that we forgive you."
Undoubtedly, it is supernatural. It could only come from a Spirit of Christianity. We can forgive, because He forgave us. He shows us a better way. A way of freedom from bitterness and punishment. Christ does it through us. Believing this brings us peace with God. And this peace gives us a desire to be at peace with others—through forgiveness.
What impossible injustices--things you've grown weary of dealing with on your own--do you need to hand over to Christ? Make a list and ask Him to lead you to full forgiveness. Pray for whatever He must do in you to free you to forgive.