The veneration of the dead, including one's ancestors, is based on love and respect for the deceased. In some cultures, it is related to beliefs that the dead have a continued existence, and may possess the ability to influence the fortune of the living. Some groups venerate their direct, familial ancestors. Certain sects and religions, in particular the Eastern Orthodox Church and Roman Catholic Church, venerate saints as intercessors with God; the latter also believes in prayer for departed souls in Purgatory.
In Europe, Asia, Oceania, African and Afro-diasporic cultures, the goal of ancestor veneration is to ensure the ancestors' continued well-being and positive disposition towards the living, and sometimes to ask for special favours or assistance. The social or non-religious function of ancestor veneration is to cultivate kinship values, such as filial piety, family loyalty, and continuity of the family lineage. Ancestor veneration occurs in societies with every degree of social, political, and technological complexity, and it remains an important component of various religious practices in modern times.
Ancestor worship exists among the Bantu in Southern Africa, the Chinese, the Japanese and in the Melanesian and the Polynesian cultures. While it existed in the cultures of Greece, Rome, Babylonia, Ancient Europe and Asia, it mainly survives in folklore, although its influence is present for example in the sraddha rites in India, the imperial ancestor cult in Japan, and the European All Souls Day customs to honour the dead.
Ancestor worship is always associated with tenacious clinging to the old ways, and in modern primitive societies is an obstacle to development. Worship of the dead, particularly of ancestors, stems from the belief that they can intervene in the affairs of the living; it is the fear that this intervention will be detrimental, or even destructive, that motivates the living to offer propitiation to the dead through prayer, ritual, and sacrifice.