Religion is a large and diverse group of practices. It may be small and bounded, with no outside contact (mystery religions), or it may spread widely, with many religious specialists, including priests, witches, shamans, gurus, imams, rabbis, monks, nuns, and bhiksus. It may have a strong sense of hierarchy, with certain people having more power than others (priests, kings, popes) or it may not (mystery religions).

Religion can be beneficial to individuals, families, communities, and states. It can improve health, education, economic well-being, and moral character, and reduce the incidence of social pathologies such as out-of-wedlock births, delinquencies and crimes, drug addictions, and prejudices. It can also promote social cohesion and peace. But it can also generate intolerance, cruelty, bigotry, and social oppression, and it may lead to violence and war.

Religions also make life as a project a little easier by protecting and transmitting the means to attain some of the most important goals imaginable. Some of these goals are proximate: they can be attained within this lifetime (a wiser, more fruitful, more charitable and successful way of living) or within the process of rebirth. But some are ultimate: they deal with the final condition of this or any other human being and of the universe itself. This dimension of religion can inspire awe, fear, and hope, but it can also fuel conflict. This is why some philosophers see religion as inherently destructive, such as Hector Avalos, who defines religion as a mode of thought and practice that presupposes the existence of, and relationships with, unverifiable forces or beings.