Religion is a cultural system of behaviors and practices, world views, sacred texts, holy places, ethics, and societal organisation that relate humanity to what an anthropologist has called "an order of existence". Different religions may or may not contain various elements, ranging from the "divine", "sacred things", "faith", a "supernatural being or supernatural beings" or "some sort of ultimacy and transcendence that will provide norms and power for the rest of life."
Religious practices may include rituals, sermons, commemoration or veneration (of God or deities), sacrifices, festivals, feasts, trances, initiations, funerary services, matrimonial services, meditation, prayer, music, art, dance, public service, or other aspects of human culture. Religions have sacred histories and narratives, which may be preserved in sacred scriptures, and symbols and holy places, that aim mostly to give a meaning to life. Religions may contain symbolic stories, which are sometimes said by followers to be true, that have the side purpose of explaining the origin of life, the Universe, and other things. Traditionally, faith, in addition to reason, has been considered a source of religious beliefs. There are an estimated 10,000 distinct religions worldwide. About 84% of the world's population is affiliated with one of the five largest religions, namely Christianity, Islam, Hinduism, Buddhism or forms of folk religion.
With the onset of the modernisation of and the scientific revolution in the western world, some aspects of religion have cumulatively been criticized. The religiously unaffiliated demographic include those who do not identify with any particular religion, atheists and agnostics. While the religiously unaffiliated have grown globally, many of the religiously unaffiliated still have various religious beliefs. About 16% of the world's population is religiously unaffiliated.
The study of religion encompasses a wide variety of academic disciplines, including theology, comparative religion and social scientific studies. Theories of religion offer various explanations for the origins and workings of religion.