Religion is a range of social-cultural systems, including designated behaviors and practices, morals, beliefs, worldviews, texts, sanctified places, prophecies, ethics, or organizations, that generally relate humanity to supernatural, transcendental, and spiritual elements—although there is no scholarly consensus over what precisely constitutes a religion. Different religions may or may not contain various elements ranging from the divine, sacredness, faith, and a supernatural being or beings.

Religious practices may include rituals, sermons, commemoration or veneration (of deities or saints), sacrifices, festivals, feasts, trances, initiations, matrimonial and funerary services, meditation, prayer, music, art, dance or public service. Religions have sacred histories and narratives, which may be preserved in sacred texts, symbols and holy places, that primarily aim to give life meaning. Religions may contain symbolic tales that may attempt to explain the origin of life, the universe, and other phenomena; some followers believe these to be true stories. Traditionally, both faith and reason have been considered sources of religious beliefs.

There are an estimated 10,000 distinct religions worldwide, though nearly all of them have regionally based, relatively small followings. Four religions—Christianity, Islam, Hinduism, and Buddhism—account for over 77% of the world's population, and 92% of the world either follows one of those four religions or identifies as nonreligious, meaning that the remaining 9,000+ faiths account for only 8% of the population combined. The religiously unaffiliated demographic includes those who do not identify with any particular religion, atheists, and agnostics, although many in the demographic still have various religious beliefs. A portion of the population, mostly located in Africa and Asia, are members of new religious movements. Scholars have indicated that global religiosity may be increasing due to religious countries having generally higher birth rates.

The study of religion comprises a wide variety of academic disciplines, including theology, philosophy of religion, comparative religion, and social scientific studies. Theories of religion offer various explanations for its origins and workings, including the ontological foundations of religious being and belief.