Forgive and Forget?
When one has forgiven another, there ought to be a complete change in the relationship that follows. That change, however, does not mean that everyone must immediately forget the past. There is no such commandment in the Scriptures.
Forgiveness is not a shock treatment that instantly wipes out memory of the recent past. On occasions there may continue to be some fear that the same transgression may be committed again. This may be true particularly where a sexual offense, such as adultery, homosexuality, or incest, has occurred. It is understandable and proper that the offended party should be somewhat wary for a time.
Nevertheless, under proper conditions forgetting (even of such unsettling offenses) will take place more rapidly than at first may be expected.
If forgetting in time does not follow forgiving, the counselor ought to look for the reason. He may find, for instance, that the offended party has been brooding over the offense in self-pity. Such brooding is decidedly unscriptural and does not fit into the biblical concept of forgiveness. Forgiveness means no longer continuing to dwell on the sin that was forgiven. Forgiveness is the promise not to raise the issue again to the offender, to others, or to himself. Brooding is a violation of the promise made in granting forgiveness.
Jay E Adams, Christian Counselor’s Manual