Therefore if that man repenteth not, and remaineth and dieth an enemy to God, the demands of divine justice do awaken his immortal soul to a lively sense of his own guilt, which doth cause him to shrink from the presence of the Lord, and doth fill his breast with guilt, and pain, and anguish, which is like an unquenchable fire, whose flame ascendeth up forever and ever. (Mosiah 2:38)I thought it was very significant that the demands of justice awakes a lively sense of guilt in unrepentant spirits; even though they have done their best to put their conscience to sleep and quell feelings of guilt during their mortal life and bury the memories in oblivion, they will get hit with a divine justice in the end, with a clear, awakened memory of everything they did and then guilt will attack. (Yikes!)
Which is why we need to repent in this life.
Don't buy society's "just move on with your life and forget about it" mantra. Guilt has to be dealt with and healed through the Atonement of Christ. Whether it is our conscience legitimately reproaching us or whether it is Satan trying to buffet us by imputing guilt where none exists, it needs to be dealt with and healed through the Atonement of Christ.