Forgiving others' trespasses against us because we know that God forgave us our sins, is easier said than done. The level of pain caused when a person wrongs us, combined with how "sorry" the person seems to be, often play the biggest role in whether or not we "choose" to forgive. It is very human to hold grudges. The Gospel tells us to treat others as we want to be treated, but this may not always lead to forgiveness. How do we want to be treated? What do we think we deserve? Although we may be aware intellectually that God have forgiven us, it may be hard to feel free from the wrongs we have done. When we feel imprisoned our sins, it is impossible to release others from the weight of the wrongs they have done to us.
God wants us to know with all of our minds, hearts and strength that God has blotted out our sins and accepts us. Christ's incredible sacrifice on the cross shows us this in the most intense way possible that he loves you enough to take on the burden of your sin so that you may be free from it and come into full relationship with God.
When we can love one another and believe God loves us enough to have completely forgiven us, then we can forgive others. The capacity to do these things comes not from ourselves, our own hard work, or our own kindheartedness. They come as gifts from God.
As we pray for the gift to be able to truly forgive, both ourselves and others, we should seek to know the love of God, the grace of Christ, and the communion of the Holy Spirit, and all these things will be added unto us.
Do all possess gifts of healing? Do all speak in tongues? Do all interpret? But strive for the greater gifts. And I will show you a still more excellent way. 1 Corinthians 12:30-31