What does the Bible say about demon possession?

TL;DR:

The Bible teaches that demon possession is real, especially for those who open themselves up to such spirituality. Believers cannot be demon possessed, but demons can still attack; so, believers are called to rely on God’s strength and His Word for protection and victory over the evil spiritual forces.

what does the bible say?

The Bible teaches that demon possession is real and is often associated with idol worship and occult practices. Demonic influence can manifest as physical ailments, like muteness or seizures, and can lead to destructive behavior, as seen in Judas Iscariot. Demons actively work against the gospel, spreading deception and false teachings (2 Corinthians 11:3–4), and idol worship is closely linked to demonic activity (1 Corinthians 10:20). Opening oneself to demon possession is dangerous and foolish. For believers, we are assured that demons cannot possess those who are saved because the Holy Spirit dwells within them. Still, demons can seek to attack and oppress or demonize believers. Believers are called to rely on God's strength for protection and victory over spiritual forces (Ephesians 6:10–18).

from the old testament

While demon possession is seen in the New Testament, we see the activity of evil spirits in the Old Testament as well (1 Samuel 16:14–23; Judges 9:23).
As many missionaries testify, demon possession seems to be connected somehow to idol worship, or interest in or ownership of occult objects or materials. This observation agrees with Scripture, as the Bible consistently assumes idols to be more than pieces of wood or metal, but representative of demons or evil spirits (Leviticus 17:7; Deuteronomy 32:17; Psalm 106:37).

from the new testament

The New Testament reveals varying details about the effects of demonic influence (Matthew 9:32–33, 12:22, 17:18; Mark 5:1–20, 7:26–30; Luke 4:33–36, 22:3; and Acts 16:16–18). Some demon possession causes physical maladies such as muteness and epilepsy, while sometimes demon possession simply causes evil behavior, as with Judas Iscariot (Luke 22:3). Other demon possession includes having supernatural knowledge (Acts 16:16–18), superhuman strength (Matthew 8:28), and depressive moods or a tendency to violence (1 Samuel 16:14–15; 18:10–11; 19:9–10).
A refusal to forgive (2 Corinthians 2:10–11), unbelief (2 Corinthians 4:4), and the spread of false beliefs or doctrines (1 Timothy 4:1–2) are all attributed to demonic influence in the Bible.
Demons are especially interested in influencing us against the gospel—the good news about Jesus Christ—and the atonement He achieved on the cross (2 Corinthians 11:3–4, 13–15; 1 Timothy 4:1–5; 1 John 4:1–3) such as when the demons who possessed a slave girl were trying to undermine Paul preaching the gospel (Acts 16:16–18).
Opening oneself up to the possibility of demon possession is foolish and dangerous. Generally, habitual sin or a hardened heart can be an entry point, as in the case of Judas (John 12:6).
First Corinthians 10:20 connects idolatry with demonic activity.

implications for today

It is important to remember that Satan and demons cannot do anything that the Lord does not permit them to do (Job 1—2). Because of this, though Satan may treat humanity cruelly, his actions will always be restricted to what is allowed by God to accomplish His purpose—Judas' betrayal being a perfect example of this principle. We should not fear demons, or try to fight them with our own strength, but fear God and fight with His strength (Ephesians 6:10–18), because He is in perfect control of the spiritual realms and is our Protector.

understand

Demon possession is real and often linked to idol worship or occult practices.
Believers cannot be possessed by demons but can be attacked or oppressed.
The Bible calls us to rely on God’s strength to resist demonic influence and fight spiritual battles.

reflect

Why do you think the Bible emphasizes the importance of relying on God’s strength rather than our own when facing spiritual battles?
How do you rely on God's strength for protection from spiritual forces of evil?
How does the reality of spiritual warfare shape your daily life and choices?

engage

Many symptoms of demon possession can be symptoms of something else, so we must be careful not to automatically assume that anyone with depression or epilepsy is being possessed by a demon. At the same time, we should not discount the possibility that demons could be involved and that there is a spiritual component to someone’s suffering or difficulty. Many Christians, especially those in Western cultures, tend not to take demon possession seriously, and this is a grave mistake. Demonic or satanic activity is much harder to recognize and eliminate when it is assumed to be something more benign. However, when we recognize that there could be a spiritual battle around us, we can address the situation spiritually as well. How can believers discern between physical or psychological issues and potential demonic influence in today’s world?
Can a Christian become demon possessed? There is never an instance of this in Scripture, and this is widely believed to be impossible due to the fact that a demon cannot reside in a vessel that is already possessed with the Holy Spirit, i.e., any believer (1 Corinthians 6:19; 2 Corinthians 1:22; 5:5). However, believers can be tormented and bothered and oppressed by demons (Matthew 16:23).
The Bible calls us to be under the influence of the Holy Spirit. Opening ourselves up to any other spirituality is dangerous and foolish. Besides idolatry and hardening one’s heart, other activities that seem to be dangerous entryways into the realm of evil spirit involvement include participation in cults, occult activity, drug and alcohol abuse, sin and immorality, rebellion, bitterness, and new age practices, including transcendental meditation or astral projection.