The power of the dead is an important aspect of religion and social control. If, for example, a Lugbara man threatened the solidarity of the clan or lineage in any of a number of ways, the elder may invoke ghosts to punish the troublemaker (Middleton 1971: 488-92). Without doubt this veneration of the ancestors and fear of their power functions importantly to help control many societies. Interestingly, ancestor worship also contributes to the conservative nature of those cultures where it is practiced. Typically, dead ancestors do not smile favorably on any kind of change in the cultures of their living relatives. Because ghosts are capable of severly punishing an earthly mortal desirous of change, the force for conformity is strong.
Not all societies assign power to ancestors. In many cultures, North America included, a high god (monothesim) or gods (polytheism) exert authority over the living, punishing those who violate religious tenets, rules that often are duplicated in civil law and serve as the bases of appropriate social behavior. In these groups ancestor cults and worship of the deceased are not found, although the spiritual nature of ancestors and belief in the afterlife persevere.
Among peoples where the deceased are believed to take an active role in society, the living are understandably concerned with the welfare of ancestors. Customs are established to assure the comfort of the dead in their life after death. Most commonly rituals carried out at funerals, burials and in some cases reburial or cremation, insure that loved ones arrive safely at what the living believe is the proper abode of the dead. The care taken in preparing the deceased for the afterlife is an important reinforcement of the society's customs and an expression among its members. Participation helps insure that the same care can be expected to be given at the time of one's own death. Beyond this motivation, however, the power to rain down misfortunes is a major reason for carefully foloowing customs surrounding the preparation, interment, and propitation of the dead. No one wants to be the subjected to supernatural punishment by vengeful and angry ghosts.
Magic, Witchcraft, and Religion Third Edition Lehmann and Myers
Picture taken by me - my great granddad, granddad and dad were hog farmers.