Religion, sacred engagement with that which is believed to be a spiritual reality. Religion is a worldwide phenomenon that has played a part in all human culture and so is a much broader, more complex category than the set of beliefs or practices found in any single religious tradition. An adequate understanding of religion must take into account its distinctive qualities and patterns as a form of human experience, as well as the similarities and differences in religions across human cultures.
In all cultures, human beings make a practice of interacting with what are taken to be spiritual powers. These powers may be in the form of gods, spirits, ancestors, or any kind of sacred reality with which humans believe themselves to be connected. Sometimes a spiritual power is understood broadly as an all-embracing reality (see Pantheism), and sometimes it is approached through its manifestation in special symbols. It may be regarded as external to the self, internal, or both. People interact with such a presence in a sacred manner—that is, with reverence and care. Religion is the term most commonly used to designate this complex and diverse realm of human experience.