Answer
While the Bible does not explicitly state whether a Christian can be possessed by a demon, related biblical truths make it clear that Christians cannot be demon-possessed. There is a clear distinction between being possessed by a demon and being oppressed or influenced by a demon. Demon possession entails a demon having direct or complete control over the thoughts and/or actions of a person (Matthew 17:14-18; Luke 4:33-35; 8:27-33). Demon oppression or influence involves a demon or demons spiritually attacking a person and/or leading them into sinful behavior. It is noteworthy that in all the New Testament passages addressing spiritual warfare, there are no instructions to cast a demon out of a believer (Ephesians 6:10-18). Believers are instructed to resist the devil (James 4:7; 1 Peter 5:8-9), not to cast him out.
Christians are indwelt by the Holy Spirit (Romans 8:9-11; 1 Corinthians 3:16; 1 Corinthians 6:19). Surely, the Holy Spirit would not permit a demon to possess the same person He is indwelling. It is inconceivable that God would allow one of His children, whom He redeemed with the blood of Christ (1 Peter 1:18-19) and transformed into a new creation “Therefore, if anyone is in Christ, he is a new creature: old things have passed away; behold, all things have become new” (2 Corinthians 5:17).
Old things have passed away; all things have become new.” (2 Corinthians 5:17). Believers may engage in spiritual warfare against Satan and his demons, but not from within themselves. The apostle John affirms, “You, dear children, are from God and have overcome them, because the One who is in you is greater than the one who is in the world” “Ye are of God, little children, and have overcome them: because greater is he that is in you, than he that is in the world.” (1 John 4:4). Who is the One within us? The Holy Spirit. Who is the one in the world? Satan and his demons. Therefore, according to Scripture, believers have conquered the realm of demons, and the argument for demon possession of a believer is not supported biblically.
With the substantial biblical evidence that a Christian cannot be demon-possessed, some Bible teachers use the term “demonization” to describe a demon exerting control over a Christian. While some suggest that a Christian cannot be demon-possessed, they can be demonized. The description of demonization is often indistinguishable from demon possession, leading to the same conclusion. Altering the terminology does not change the reality that a demon cannot reside in or fully control a Christian. Demonic influence and oppression are genuine for Christians, but it is not scriptural to claim that a Christian can be possessed or demonized.
The rationale behind the concept of demonization often stems from personal encounters with individuals who were believed to be Christians but displayed signs of demon control. It is essential, however, not to let personal experiences dictate our understanding of Scripture. Instead, we should interpret our experiences through the lens of biblical truth (2 Timothy 3:16-17). Observing an individual whom we believed to be a Christian displaying behaviors associated with demonization should prompt us to question the authenticity of their faith. It should not lead us to reconsider whether a Christian can be possessed by a demon or demonized. It is possible that the individual is genuinely a Christian but is under severe demonic oppression and/or struggling with significant psychological issues. Nevertheless, our personal encounters must align with the standards set by Scripture, not the other way around.