Forgiveness is acknowledging who God is and that it is HIS place to judge and to deal with sin -- both mine and others. I can and should be hurt and angry over sin and injustice, whether directed at me or others, but I need to allow God to deal with the sinner, not dispense punishment myself. When I refuse to forgive, or to hand the matter over to God to handle, I am putting myself in the place of God. I walk in darkness instead of in God's light, and I am blinded by my unforgiveness. When I let go of my pride and unbelief and instead trust in God -- to the point I can say "Though He slay me, yet will I trust Him" -- I can forgive others and live in God's light.