What is demonic oppression?

TL;DR:

Demonic oppression is the external influence of demonic forces causing emotional, psychological, or physical distress in a person. While demons can oppress or demonize, they are ultimately subject to the authority of Christ.

what does the bible say?

Demon oppression, or more properly demonization, as described in the Bible, is a real and multifaceted issue. Both the Old and New Testaments confirm the existence and activity of demons, with instances ranging from severe possession to more subtle forms of influence. Major demonization, as seen in the man with the legion of demons, represents extreme cases where the individual seems overtaken by demonic forces. Minor forms, like the subtle influence over Ananias and Sapphira, can be less overt but still harmful. Despite the reality of demonic oppression, Scripture emphasizes that Jesus has ultimate authority over demons, having defeated them and disarmed their power (Colossians 2:15). Christians are assured of their protection and authority in Christ, which empowers them to stand firm against demonic forces through spiritual armor and Christ-centered focus (Ephesians 6:11–12).

from the old testament

The Old Testament affirms the existence of demons (1 Samuel 16:14–15; 1 Kings 22:19–23).

from the new testament

The New Testament also affirms the existence of demons (Matthew 4:23–25; Mark 1:34; Luke 8:30–33; Acts 16:16-18, etc.).
The word used to describe demonic activity in the life of a person is daimonizo, which is correctly translated "demonized.” This demonization can be major or minor. In the case of the man with the legion of demons in Mark 5 and Luke 8, we see major demonization that 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 speaks of demons being able to cause sickness or other physical infirmities (e.g. Matthew 9:32; Luke 13:11), supply apparent clairvoyant or fortune telling 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 that God is sovereign over demons and that Jesus possesses full authority over the enemy (Mark 1:27).
"[God] disarmed the rulers and authorities [demons] and put them to open shame, by triumphing over them in [Christ]" (Colossians 2:15).
Christians need to know "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).
Christ is the One who provides the authority and power over demonic oppression—not the particular individual (Luke 10:19; Acts 19:13–15; 1 John 4:4; 1 John 5:18).
James 4:7 counsels, “Submit yourselves therefore to God. Resist the devil, and he will flee from you” (see also 1 Peter 5:6–11).

implications for today

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). While the Bible confirms the truth that demons can afflict humanity, it also speaks to the fact that Christians are secure in Christ and need not be defeated by demons. 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."

understand

Both the Old and New Testaments confirm that demons can cause significant distress.
Oppression can range from severe possession to subtle influence, affecting individuals in different ways.
Jesus has defeated demons, and Christians have the power and protection to resist them.

reflect

How do you personally recognize and respond to the subtle forms of demonic oppression through emotional or psychological distress?
How does understanding the authority of Christ over demonic forces impact your approach to handling personal or others' struggles with distress?
How does the concept of spiritual armor and Christ-centered focus help you in your daily life to resist or overcome difficulties?

engage

The actual Greek term used to describe a demonic presence in the life of a person is daimonizo, which is correctly translated "demonized,” not oppressed or possessed. 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.
How do the manifestations of demonic oppression in Scripture inform our understanding of its impact on both individuals and communities today?
How does the biblical distinction between severe and subtle forms of demonic influence shape our approach to spiritual warfare and pastoral care?