The Bible affirms the existence of demons numerous times in both the Old and New Testaments (e.g., 1 Samuel 16:13-15, 1 Kings 22:19-23, Luke 8:30-33, Acts 16:16-18, etc.). In addition, the Bible speaks about the influence that demons can have in the lives of human beings.
What is demonic oppression?
Some have tried to confine the work of demons in the lives of humanity to that of "demon possession," with this thought being further propagated by poor English translations of the Greek New Testament that use the word "possession" in various verses that describe demon activity. However, the fact is that the actual Greek term used to describe a demonic presence in the life of a person is daimonizo, which is correctly translated "demonized."
In other words, Scripture in no way limits the work of demonic powers to only that portrayed in movies such as The Exorcist, where a person is completely held hostage by the enemy so much so that he or she cannot function and, for all practical purposes, ceases to exist as his or her own person. Instead, the Bible, in various places, speaks of a person having an "unclean spirit" that negatively influenced or affected his or her life in some way, either major or minor.
For example, the well-known story of the man with the legion of demons in Mark 5 and Luke 8 is a case of demonization that had progressed to the point of the individual appearing to be fully owned by the enemy. On the other hand, in Acts 5, the instance of Ananias and Sapphira having their hearts "filled by Satan" is a more subtle and mild illustration of demonic oppression (even though that "mild" oppression cost them their lives).
Scripture also speaks of demons being able to cause sickness or other physical infirmities (e.g. Luke 13:11, Matt. 9:32), supply apparent clairvoyant or fortunetelling powers (Acts 16:16), exert great strength and become violent toward others (Acts 19:16), and bring physical harm to a so-called host (Mark 9:14-29).
While the Bible is clear that demonization is real, it also unmistakably communicates the truth that God is sovereign over demons and that Jesus possesses full authority over the enemy. The gospels show that a hallmark of Jesus' ministry while He was on earth was His conquering of the powers of darkness in a very public way, so much so that the crowds were amazed and said, "He commands even the unclean spirits, and they obey Him" (Mark 1:27).
This fact leads to a number of important truths that Christians should always keep at the forefront of their minds when the subject of demonization comes up. First, believers should understand Christ's position and His victory over the enemy. Scripture says, "He disarmed the rulers and authorities [demons] and put them to open shame, by triumphing over them in him" (Colossians 2:15), and "what is the immeasurable greatness of his power toward us who believe, according to the working of his great might that he worked in Christ when he raised him from the dead and seated him at his right hand in the heavenly places" (Ephesians 1:19–21).
Jesus is seated above all demonic powers and fully destroyed the work of Satan, as the Bible says: "The reason the Son of God appeared was to destroy the works of the devil" (1 John 3:8).
Next, not only is Christ seated above all the demonic realm (indicating his authority over them), but so are believers: "But God, being rich in mercy, because of the great love with which he loved us, even when we were dead in our trespasses, made us alive together with Christ—by grace you have been saved— and raised us up with him and seated us with him in the heavenly places in Christ Jesus" (Ephesians 2:4-6, emphasis added). This means that all Christians, by their position in Christ, have authority over Satan's army.
Of course, it is Christ who provides the authority and power, and not the particular individual. This truth is explicitly manifested in numerous verses throughout Scripture, including the following:
"Little children, you are from God and have overcome them, for he who is in you is greater than he who is in the world" (1 John 4:4).
"We know that everyone who has been born of God does not keep on sinning, but he who was born of God protects him, and the evil one does not touch him" (1 John 5:18).
"God gave us a spirit not of fear but of power and love and self-control" (2 Timothy 1:7).
"Behold, I have given you authority to tread on serpents and scorpions, and over all the power of the enemy, and nothing shall hurt you" (Luke 10:19).
Lastly, Christians need to understand their protection in Christ. Paul writes, "Put on the whole armor of God, that you may be able to stand against the schemes of the devil. For we do not wrestle against flesh and blood, but against the rulers, against the authorities, against the cosmic powers over this present darkness, against the spiritual forces of evil in the heavenly places" (Ephesians 6:11-12).
So, while the Bible confirms the truth that demons can afflict humanity, it also speaks to the fact that Christians have authority and power over demons and need not be defeated by them. The proper mindset for victory is to be Christ-centered, which is something spelled out well by A. W. Tozer in his book Born After Midnight:
"The scriptural way to see things is to set the Lord always before us, put Christ in the center of our vision, and if Satan is lurking around he will appear on the margin only and be seen as but a shadow on the edge of the brightness. It is always wrong to reverse this – to set Satan in the focus of our vision and push God out to the margin. Nothing but tragedy can come of such inversion … The best way to keep the enemy out is to keep Christ in … It is not the praying sheep Satan fears, but the presence of the shepherd."
Why does God allow Satan and the demons to attack us?
What does the Bible say about demon possession?
Is it possible for a Christian to be demon-possessed?
What are demons according to the Bible?
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Truth about Angels