And when you stand praying, if you hold anything against anyone, forgive him, so that your Father in heaven may forgive you your sins. —Mark 11:25
Forgiveness is a choice we must make, and it is not a choice that comes easily. If it were easy, why do you think Jesus would mention it again after He finished the Lord's Prayer? He knows forgiveness is difficult. It wasn't easy for God to do what He did either, but He did it anyway. He sacrificed His Son, and He asks us to make a little sacrifice in return. You must make the choice to let your enemies off the hook and even pray that God will let them off the hook. When you do that and really mean it, you are there. He looks down from heaven and says good. But then you have to do it again tomorrow. You must make the choice and live it out. Love is an act of the will.
Making a choice to continue in unforgiveness shows that we aren't sufficiently grateful for God's forgiveness of our own sins. Perhaps we haven't taken seriously enough our own sin or our own redemption. Probably what we all want to say is, "Well, what I did wasn't nearly as bad as what they have done!" And that's where we are wrong! God hates self-righteousness as much as He hates the injustice that you think is so horrible, and He certainly doesn't like it when we judge. So if you must forget the sins of which God has forgiven you, at least remember that one of the most heinous sins of all is self-righteousness.
There is, however, another cause for unforgiveness: that we don't put a high enough value on our relationship with the Father. There should be nothing more important to us than our relationship with God. If you choose to withhold forgiveness from others, you are not putting a high enough value on things today that one day will mean everything to you.
Excerpted from Total Forgiveness (Charisma House, 2002).