I have heard the statement for as long as I can remember.
In fact, I've probably said it myself.
Often this statement comes when someone is dealing with the conviction of past sin. For Christians, the statement seems normal, but it is far from God's design.
"I know God has forgiven me. I just can't forgive myself."
Last night, as I led our GriefShare group here at church, the video teaching was focusing upon the uniqueness of grief that people experience. In the midst of the presentation, the reality of false and true guilt was surfaced. There are times that we feel guilty for things we have done, or not done, and cannot seem to get past that. In prayer, we seek forgiveness from God and mentally acknowledge the Bible's statement that our sins are forgiven through Christ when we repent. But, the Accuser is still at work and to disavow the spiritual attacks is dangerous.
You and I do not have the capacity to forgive ourselves. The relief is that we are not expected to do so. Our responsibility is to receive the forgiveness offered from God. When we repent of our sins, following the conviction by the Holy Spirit, God is faithful and just to forgive our sins.
To hold onto that guilt actually is a form of idolatry. It places self on the throne and relegates God to a subservient role.
Even Christians do this.
While not an easy concept to grasp, especially since most of us have heard the "I can't forgive myself" mantra our entire lives (even from Christians, and maybe even from ourselves) it is time to let God have this completely and disavow any false guilt placed upon us from the Enemy.