When the doer is dead Karma is useless; in order for Karma to become useless we have to forgive those that trespass against us. In order to forgive those that trespass against us we have to forget their wrong doings, one forgets the wrong doings of their neighbor when one comprehends. One comprehends when one apprehends right thought, right feelings and right action with the consciousness, otherwise, one develops resentment, which is the memory of the neighbor’s wrong doing against us. And that memory creates Karma.