In Mormonism, Satan (also called Lucifer) is viewed as one of Heavenly Father’s spirit children — a brother to Jesus and to all human beings. In the premortal existence, he rebelled against God’s plan by seeking to remove human agency and force everyone to return to God. Because of his rebellion, he and his followers were cast out of heaven and denied the opportunity to receive physical bodies.
Latter-day Saints believe Satan continues to tempt and deceive people, opposing God’s plan by trying to make humanity miserable and lead them away from truth. His power, however, is seen as limited to this mortal life.
Biblical Christianity teaches that Satan is a created angel who rebelled against God (Isaiah 14:12–15; Revelation 12:7–9). He is not related to Jesus or humanity by nature or origin. Scripture presents him as a personal, powerful adversary whose goal is to destroy faith, yet who was ultimately defeated by Christ’s death and resurrection.
