Animism is the belief that all things in creation have a spirit. Animists commonly perform rituals to stay in harmony with the spirits of nature and with the spirits of their ancestors. Animism was the primary religion of most peoples of the world until the advent of modern religions such as Judaism, Hinduism, Buddhism, Christianity and Islam. The remnants of animistic beliefs can still be found in various actions designed for protection from evil spirits, such as placing a horseshoe over a doorway or knocking on wood. Customs that originated with animistic beliefs include decorating a Christmas tree and hanging a sprig of mistletoe.