Indigenous South American religions are as varied as the languages and cultures in which they are embedded. Although many of these traditions have either been altered or even become extinct since their first interaction with Europeans, many still exist in variant forms throughout the continent, including in communities where Christianity has long been present. The religious diversity among these indigenous traditions is great, but some commonalities exist among them. Most of these traditions have creation mythologies that describe not only the creation of the world, but also the many spiritual beings active in the world. Some indigenous South American traditions believe in a supreme being who creates the world, while others believe the world came out of nothing. Many rituals and ceremonies within these traditions center on the calendar and the stars, and these rituals can be related to the activities of spiritual beings as well as to other aspects of nature. Many South American religious traditions practice various initiation rites for both men and women, rituals that help define the role of the individual within the community. Some of the traditions also have persons of religious and spiritual authority such as priests, diviners, and shamans.