Many people have asked, “Can a Christian be possessed by a demon?” In order to answer this adequately we must be clear on what possession is – the state of being completely controlled by a demon in every respect. It is not possible for a born again Christian to be possessed in the same way as a lost person can be. But things get a little more complex from here, as we will see.
While it is not possible for a genuine believer to be completely possessed, there can be various levels of oppression, some quite serious. These can be very subtle (Gen. 3:1), so as to be almost undetectable, or they can take the form of an increased intensity of temptation, strong disordered thoughts, feelings or impulses that seem too powerful to resist, auditory or visual impressions, fears of hell or losing salvation.
One source of confusion in this matter is that Bible translations have often described people as ‘possessed’ when the best rendering would be that a person had a demon, was demonized or was troubled by a demon.
When talking about the demonic affliction of believers, we favor a descriptive approach rather than one that relies on terminology that can be misunderstood or argued over. Rather than using a certain word like possessed or demonized, we prefer to talk about a person being oppressed or troubled by the demonic. So here is a summary of our teaching on demonic activity and Christians:
 We don’t use the word “possessed” to refer to the oppression of Christians. This just creates confusion. We usually say something like this believer is dealing with demonic oppression or seems to be oppressed.
 Believers are often afflicted by demonic entities, though the type of affliction can vary widely, from being unnoticeable to the average person (even the person who is being oppressed), to being fairly obvious. Deep, long term demonization can result in a condition that can closely resemble possession.
 Any area of the believer’s life can be affected. We may see relationship trouble, sleeplessness, sickness, compulsions, addictions, emotional trouble, or lack of ability to function at home, work or church. Indeed, almost any physical, emotional, relational, mental or spiritual disorder can be the result of demonic oppression.
Of course, the previous sentence could also be said of the effects of stress or various psychological conditions, so this is one important reason why spiritual discernment is a very important component of deliverance ministry.