What are the differences between demon, devil, and Satan? Are they the same entity?

People’s beliefs concerning Satan range from the silly to the abstract — from a little red guy with horns who sits on your shoulder urging you to sin, to an expression used to describe the personification of evil. The Bible, however, gives us a clear portrait of who Satan is and how he affects our lives. Put simply, the Bible defines Satan as an angelic being who fell from his position in heaven due to sin and is now completely opposed to God, doing all in his power to thwart God’s purposes.

Satan was created as a holy angel. Isaiah 14:12 giving Satan’s pre-fall name as Lucifer. Ezekiel 28:12–14 describes Satan as having been created a cherub. He became arrogant in his beauty and status and decided he wanted to sit on a throne above that of God (Isaiah 14:13–14; Ezekiel 28:15; 1 Timothy 3:6). Satan’s pride led to his fall. Notice the many “I will” statements in Isaiah 14:12–15. Because of his sin, God permanently removed Satan from his exalted position and role.

Satan became the ruler of this world, earth and the prince of the power of the air (John 12:31; 2 Corinthians 4:4; Ephesians 2:2). He is an accuser (Revelation 12:10), a tempter (Matthew 4:3; 1 Thessalonians 3:5), and a deceiver (Genesis 3; 2 Corinthians 4:4; Revelation 20:3). His very name means “adversary” or “one who opposes.” Another of his titles, the devil, means “slanderer.”

Even though he was cast out of heaven, he still seeks to elevate his throne above God. He counterfeits all that God does, hoping to gain the worship of the world and encourage opposition to God’s kingdom. Satan is the ultimate source behind every false cult and world religion. Satan will do anything and everything in his power to oppose God and those who follow God. However, Satan’s destiny is sealed — an eternity in the lake of fire (Revelation 20:10).

Demons are fallen angels, as Revelation 12:9 indicates: “And the great dragon was cast out, that old serpent, called the Devil, and Satan, which deceiveth the whole world: he was cast out into the earth, and his angels were cast out with him.”

Satan’s fall from heaven is symbolically described in Isaiah 14:12–15 and Ezekiel 28:12–15. When Satan fell, he took some of the angels with him — one third of them, according to Revelation 12:4. Jude 6 also mentions angels who sinned. So, biblically, demons are fallen angels who, along with Satan, chose to rebel against God.

Some of the demons are already locked “in darkness, bound with everlasting chains” (Jude 1:6) for their sin. Others are free to roam and are referred to as “the powers of this dark world and . . . the spiritual forces of evil in the heavenly realms” in Ephesians 6:12 (cf. Colossians 2:15). The demons still follow Satan as their leader and do battle with the holy angels in an attempt to thwart God’s plan and hinder God’s people (Daniel 10:13).

Demons, as spirit beings, have the ability to take possession of a physical body. Demonic possession occurs when a person’s body is completely controlled by a demon. This cannot happen to a child of God, since the Holy Spirit resides in the heart of the believer in Christ (1 John 4:4).

Jesus, during His earthly ministry, encountered many demons. “When the even was come, they brought unto him many that were possessed with devils: and he cast out the spirits with his word, and healed all that were sick:” Matthew 8:16.

Jesus’ authority over the demons was one of the proofs that He was the Son of God (Luke 11:20). The demons who encountered Jesus knew who He was, and they feared Him: “And, behold, they cried out, saying, What have we to do with thee, Jesus, thou Son of God? art thou come hither to torment us before the time?’” Matthew 8:29. Demons know their end will be one of torment.

Satan and his demons now look to destroy the work of God and deceive anyone they can (1 Peter 5:8; 2 Corinthians 11:14–15). Demons are described as evil spirits (Matthew 10:1), unclean spirits (Mark 1:27), lying spirits (1 Kings 22:23), and angels of Satan (Revelation 12:9). Satan and his demons deceive the world (2 Corinthians 4:4), promulgate false doctrine (1 Timothy 4:1), attack Christians (2 Corinthians 12:7; 1 Peter 5:8), and combat the holy angels (Revelation 12:4–9).

Demons/fallen angels are enemies of God, but they are defeated enemies.