Scripture tells us to forgive

Forgiving one another, even as God in Christ forgave you. (Ephesians 4:32 NKJV)

 Understanding that Scripture tells us to forgive others, and agreeing that we should do so, is one thing. But the act of forgiving someone who has deeply wounded us can be a difficult and gut-wrenching task.
 The Greek word most often translated as forgiveness is “aphiemi”, which is used to express letting something go, or cancelling a debt. When we forgive someone for what they have done, we release them from a legitimate debt. We acknowledge that we’ve been injured or wronged, our trust has been betrayed, and our life has been marred by someone else’s hurtful actions.
 But we also understand that we too are sinners, that we offend and hurt others, and that we’ve been forgiven for our offenses by God. When we forgive, we make the decision to let go of our pain, our desire for retribution, our anger and negative feelings toward the person. We put the person, and their actions, into God’s hands.
 It can be natural to feel that forgiving someone is equivalent to excusing them for what they have done. Not so. Rather it sets you free to let go of the pain of the offense, to move on without your feelings of ill will toward the person who harmed you constantly plaguing you.
 We must forgive others for their trespasses against us—as hard as it may sometimes be—because God has forgiven our trespasses against Him. —Peter Amsterdam [1]

 Everyone says forgiveness is a lovely idea, until they have something to forgive. —C.S. Lewis

[1] Activated The Call to Forgive