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. Other religious groups, however, consider veneration of the dead to be idolatry and a sin.
In European, Asian, Oceanian, 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 reverence is not the same as the worship of a deity or deities. In some Afro-diasporic cultures, ancestors are seen as being able to intercede on behalf of the living, often as messengers between humans and God. As spirits who were once human themselves, they are seen as being better able to understand human needs than would a divine being. In other cultures, the purpose of ancestor veneration is not to ask for favors but to do one's filial duty. Some cultures believe that their ancestors actually need to be provided for by their descendants, and their practices include offerings of food and other provisions. Others do not believe that the ancestors are even aware of what their descendants do for them, but that the expression of filial piety is what is important.
Most cultures who practice ancestor veneration do not call it "ancestor worship".