What do you do with the person who says, “I’ve asked God to forgive me about this, but I still feel guilty”? I hear that statement over and over again. I usually say to these people, “If you still feel guilty, then pray to God again. But this time don’t ask Him to forgive you for the sin that is haunting you. Rather, ask Him to forgive you for insulting His integrity by refusing to accept His forgiveness. Who are you to refuse to forgive yourself when God has forgiven you? When God promises to forgive His people when they repent, He is not playing games. If He says He will forgive you, then He will forgive you. And if God forgives you, you are forgiven.”
R.C. Sproul