Today a belief in evil spirits is considered to be foolish superstition in many western developed countries, but in most parts of the world and for all of human history most people have believed not only in their existence, but also in their evil influence in their everyday lives. Since spirits by their very definition are invisible and intangible, it is impossible to prove or disprove their existence, but their reality is one of the clearest teachings of the Bible, which provides a surprising amount of information about these destructive beings.

The first mention of an evil spirit is the “distressing spirit from the Lord” that tormented king Saul, causing him to be depressed and to try to kill David (1 Samuel 16:14-23, 19:9). In another Old Testament story a lying spirit entered some false prophets, causing them to give a deceptive message to Ahab, the wicked king of Israel so that he would be destroyed (1 Kings 22:19-25).

Jesus taught that “unclean spirits” make their home in humans, where they can cause unruly behavior, inability to hear or speak, epilepsy, fever and other now recognized medical conditions. If they are cast out they try to come back and to bring other spirits with them (Matthew 12:43-45).  It is possible for one person to host more than one demon–one man had a “legion” of spirits (a Roman legion consisted of about 6,000 soldiers! Mark 5:1-19).

Jesus frequently and easily cast out evil spirits. The spirits recognized His power, divinity and authority over them (Mark 1:23-27) and begged Him not to cast them out.  They also understand that there is an appointed time in which they will be destroyed (Matt. 8:28-32). Jesus gave his followers authority over evil sprits, and they were also able to cast them out, although in some cases fasting and prayer were required for particularly stubborn spirits (Mark 9:25-29). Casting out of Spirits is one of the “signs that follow those who believe” (Mark 16:17).

The apostle Paul calls evil spirits “principalities, powers, the rulers of the darkness of this age, spiritual hosts of wickedness in the heavenly places” (Ephesians 6:12). He informs us that we are protected from them by wearing the “heavenly armor”—truth, righteousness, the gospel message, faith, assurance of salvation, the Holy Spirit and the Word of God (Ephesians 6:13-17). The apostle James assures us that if we resist evil spirits they will flee from us (James 4:7).

On the other hand, Evil Spirits can gain access to people by indulgence in sin (1 John 3:8), by unbelief (2 Corinthians 4:3,4), by rejecting the truth (2 Thess. 2:10) and through false miracles (2 Thessalonians 2:9, Revelation 16:14). Many people who have studied this subject are also convinced that Satan can gain access to people through participation in satanic rituals, dabbling in the occult, magic or witchcraft, listening to satanic music, from vows and curses, through satanic addictions such as drugs or pornography, and even as an inheritance from parents who have been demonized.

Where did evil spirits come from? Revelation 12 tells us that when Satan was cast out of heaven “his angels were cast out with him” (Revelation 12:9). Like Satan, they were perfect when they were created (Ezekiel 28:15) but no doubt they shared in the same pride, self-exaltation and dissatisfaction with God’s government that led to Satan’s downfall (Ezekiel 28:16,17, Isaiah 14:12-14).

According to Revelation, they will play a major role in the events at the end of time, deceiving “the kings of the earth” and “those who received the mark of the beast” so that they will oppose God and war against His true people, all the while believing that they are serving Him (Revelation 16:13,14, 19:19,20, John 16:2).

Even now some evil spirits who have been cast out of humans are bound in “chains of darkness” in “hell” (Greek Tartarus) (2 Peter 2:4), also known as “the abyss” or “bottomless pit” (Luke 8:31). During the Time of Trouble the abyss will be opened and the evil spirits will come out to cause misery and destruction (Revelation 9:1-6).

But at the Second Coming of Christ they will again be “chained” in the abyss—they will be confined to the ruined and depopulated earth during the thousand year millennium (Revelation 20:1-3). During the Millennium God’s people who have been saved will judge the evil angels (1 Corinthians 6:3). In the final executive judgment Satan and his followers will be “cast into the lake of fire” (Revelation 20:10) where they will be totally destroyed “and shall be no more forever” (Ezekiel 28:19).

How should we relate to these evil spiritual powers? First and most important, we must be aware of their presence and of how they work. John said we should “test the spirits, whether they are of God” and Paul said that we should “not be ignorant of (Satan’s) devices” (1 John 4:1, 2 Corinthians 2:11).

One basic thing we should know is that as believers we have power and authority over evil spirits—Jesus said “In my name (you) will cast out demons”; “I give you the authority to trample on serpents and scorpions and over all the power of the enemy” and his followers reported, “even the demons are subject to us in Your name” (Mark 16:17, Luke 10:17,19).

Satan and his demons will try to deceive believers into thinking that they have such great power that believers should be afraid of them and try to have nothing to do with them, but the Bible teaches that we should aggressively confront and defeat the enemy in our own lives and in the lives of those around us.

However, the battle with evil spirits is not our highest priority.  Jesus said that we should not rejoice that the spirits are subject to us, but rather that “our names are written in heaven” (Luke 10:20). In other words, it is possible to get so wrapped up in confronting and casting out demons that we forget that our priority and focus should be on the Lord Jesus, on His sacrifice, grace and forgiveness and on his commandment to share the gospel with the world.

As we go into the world we will surely have to confront the power of the enemy, including evil spirits. But we should always remember the words of the apostle John, “You are of God, little children, and have overcome (the evil spirits), because He who is in you is greater than he who is in the world” (1 John 4:1-4).