Syncretism refers to the fusion of different belief systems, particularly in religion. It involves adding elements of one religion to a dominant religion to create a new system. Examples include Gnosticism emerging from the influences of Judaism, Christianity, and Greek philosophy. Voodoo combined elements of African, Catholic, and Native American traditions without a single scripture or authority. Santeria merged aspects of Yoruba mythology brought by slaves with Catholicism and indigenous American traditions, involving worship of Orisha spirits and animal sacrifice. The Bible warns against syncretism, saying we should worship God in spirit and truth alone rather than blending paganism with religious truth.