In Mormonism, demons are believed to be the disembodied spirits who followed Lucifer in the premortal life. These spirits were cast out of heaven and denied physical bodies because they rebelled against Heavenly Father’s plan and chose Satan’s alternative. They now serve as tempters and deceivers, seeking to influence mortals to sin and reject truth.
Because demons are seen as spirit children of God who lost their opportunity for a physical body, they are not considered fallen angels as in traditional Christianity. Their goal is to make others as miserable as they are by leading them away from righteousness and eternal progression.
Biblical Christianity teaches that demons are fallen angels who rebelled with Satan against God (Revelation 12:9). They are powerful spiritual beings opposed to God’s purposes, yet they remain under his authority. Their goal is to destroy faith, deceive people, and oppose the work of Christ (1 Peter 5:8; Ephesians 6:12). Unlike Mormonism, the Bible does not teach that demons are spirits of unborn humans but rather angels who sinned and await final judgment (2 Peter 2:4).
Also see: Satan, Outer Darkness.