Evil spirits are referred to in both the Old and New Testaments but are often called by other names such as “unclean spirits” or “impure spirits,” “deceiving spirits” or “lying spirits,” “demonic spirits,” and “demons.” In all cases, evil spirits are malevolent supernatural beings. Evil spirits work against God, but the Bible also informs us that God in His sovereignty can choose to use evil spirits to carry out His plans and purposes, demonstrating that He is Ruler over all the universe.
The Bible does not reveal the origin of evil spirits. They are most likely angels who fell with Satan (Matthew 25:41; Revelation 12:7–9). While evil spirits exist as part of the hierarchy of evil (Ephesians 6:12) with Satan as their leader (Matthew 12:24), they are powerless to withdraw entirely from God’s rule.
Most of the evil spirits mentioned in the Old Testament were sent from God as a punishment on disobedient humans (1 Kings 22:20–23). In Judges 9:23, an evil spirit was used by God to judge Abimelech and avenge the murder of Gideon’s sons. God is not the author of evil, but He can allow evil powers, subject to His control, to bring about certain consequences in accordance with His plan.
The Lord sent an evil spirit to show that He had rejected Saul as king. The evil spirit caused Saul to experience fits of temper and despair: “Now the Spirit of the LORD had left Saul, and the LORD sent a tormenting spirit that filled him with depression and fear. Some of Saul’s servants said to him, ‘A tormenting spirit from God is troubling you’” (1 Samuel 16:14–15, NLT).
In the New Testament, the term demon is often used interchangeably with evil spirit. These wicked entities defile and bring evil to human subjects. Their intention may be to inflict physical harm, disability, and sickness rather than moral corruption.
Jesus Christ cast out evil spirits from people possessed by them (Matthew 8:16; Mark 5:1–13; 7:24–30) and gave His disciples power to do the same in His name (Matthew 10:1; Acts 5:12–16; 8:4–8; 16:18). Evil spirits know who Jesus is and that He will judge and condemn them in the future (Matthew 8:29; Mark 1:24; 5:7).
In the end times, many people will be deceived by evil spirits and the false teachings they inspire (1 Timothy 4:1). The book of Revelation speaks of deceptive evil spirits playing a significant role in the last days: “And I saw three evil spirits that looked like frogs leap from the mouths of the dragon, the beast, and the false prophet. They are demonic spirits who work miracles and go out to all the rulers of the world to gather them for battle against the Lord on that great judgment day of God the Almighty. ‘Look, I will come as unexpectedly as a thief! Blessed are all who are watching for me, who keep their clothing ready so they will not have to walk around naked and ashamed.’ And the demonic spirits gathered all the rulers and their armies to a place with the Hebrew name Armageddon” (Revelation 16:13–16, NLT).
In Luke 11:24–26, we come across an example of evil spirits that are associated with moral evil. Jesus tells a parable to illustrate that defeating Satan and casting out evil spirits is not the ultimate goal of the Christian’s life. True disciples must do more than merely sweep away unclean spirits. To keep evil from setting up camp in our spiritual houses, we must fill our lives with the good things of God and His Kingdom.
Evil spirits are never to be regarded neutrally. They are part of Satan’s dark forces, enemies of God and His people. Evil spirits promote corruption, malice, and depravity in the world and in humans. They are opposed to God’s holiness, goodness, righteousness, light, and love. As the antithesis of the Holy Spirit, evil spirits represent the opposite of God’s character, nature, and will. They are hostile to the work of God and Jesus Christ, and believers are always to resist them: “Be alert and of sober mind. Your enemy the devil prowls around like a roaring lion looking for someone to devour. Resist him, standing firm in the faith” (1 Peter 5:8–9; see also Ephesians 6:13; James 4:7).