I write this post with some trepidation, as the mentally ill have for many, many years been accused of demonic possession and treated harshly. I have seen in the news where brutal “exorcisms” have been performed on the sick, sometimes leading to death – a few of these are listed on the website “What’s the Harm“. I also know of schizophrenic people who, in the onset of their illness, were the recipients of exorcism and prayer to the exclusion of medical treatment. For those of us with diagnosed mental illnesses we sometimes find others accusing us of being demonised, of being influenced by Satan, of being more sinful and unclean than others, and castigated for taking medication and accepting psychiatric treatment.
For these reasons, then, I have avoided talking about demons before now. For years I have struggled with the very idea of demons and Satan – growing up I was assured that these things were fairy tales, and that the demon possessions in the Bible were really undiagnosed mental illness. In some ways my belief has changed. For one, it is quite strange to say that I believe in God, but somehow believing in demons is irrational – given that the Bible quite clearly talks about demons. I also have to contend with the fact that, even if all other Biblical figures made the mistake of assuming mental illnesses were demons, Jesus himself accepted and acknowledged the presence of demons and their ability to possess others. I cannot discount what he himself did – because I will not say that he was mistaken, that they weren’t really demons, that he was influenced so much by the culture of his time that he thought they were and that we know better. As a Christian I believe Jesus was God incarnate, and therefore that he could not be mistaken due to cultural and historical knowledge at the time, and nor do I believe that he would lie so that the people of his time would understand. So, then, I am somewhat reluctantly forced to acknowledge the presence of demons and Satan in the world, although I have yet to see anyone – whether mentally ill or not – who I thought was possessed or influenced.
So what do we know about demons? We know that there are certain physical manifestations of demon possession including muteness (Matthew 9:32; 12:22; Mark 9:17, 25; Luke 11:14); deafness (Mark 9:25); blindness (Matthew 12:22; John 10:21); convulsions (Mark 1:26; 9:26); superhuman strength (Mark 5:4); and self-destructive behaviour (Matthew 17:15). Something important to note here is that certain physical maladies are described as being demonic in origin for example in Luke 13:11 we meet a woman who was crippled by a demon. It seems odd, then, that many of those who call the mentally ill possessed or influenced by demons do not target their exorcisms at those with physical diseases, but instead accept medical advice in those cases. That said, there are instances in the Bible where the possessed person has some symptoms of mental illness, for example the Gerasene demoniac of Mark 5 self harmed, and was clearly in mental distress. (I have written more on this particular passage in “The Gerasene Demoniac and Self Harm”)
One thing I think is particularly important to note, and which sometimes gets lost, is that the Bible clearly distinguishes between illness and possession. For example Matthew 4:24 states:
News about him [Jesus] spread all over Syria, and people brought to him all who were ill with various diseases, those suffering severe pain, the demon-possessed, those having seizures, and the paralysed.
Here we can see a distinction being made – even though demons can produce seizures (Mark 1:26; 9:26) there are people who have seizures who are not demon possessed. As an aside, the King James Version renders “those having seizures” as “those which were lunatick” as epilepsy was supposed to come and go with the changing of the moon. It doesn’t seem that the text itself supports the idea that those who have seizures are mentally ill, though it would be really handy if it specifically talked about mental illness!
So, how do we know if someone has a demon, or if they are mentally ill? Nick Lane, quoted in the book “Depressed or Possessed? Christians Recognising and Responding to Mental Illness”  has a few questions we can ask ourselves:
- Take a history. Has there been extensive involvement in witchcraft or the occult? But be aware that in Acts 19:18 those occultists needed to confess their sin rather than be exorcised, therefore involvement does not necessarily mean possession.
- Are the symptoms atypical of psychiatric or physical illness? Are there explanations other than demonic possession?
- Is there agreement between level-headed Christians who have spent time praying and seeking the will of God on the matter?
- Remember that Jesus only exorcised when asked to do so or when manifestations occurred in front of him – he did not go to people and tell them that they needed to be exorcised.
I myself have never seen anyone who I thought had a demon – I tend to the view that, just as in the Old Testament, such possessions are rare, and that they were particularly present during the ministry of Christ because, well, the Son of God was walking with men and it was a special time. As I said above, somewhat reluctantly I have to believe in the existence of demons and that people can be possessed by them, because the Bible says so. I am very aware of the times people have said that I have a demon (this, usually because I disagreed with them about mental illness) and the way in which people can be prevented from accessing psychiatric treatment because they think they must be possessed. I would say that any “possession” which responds to medical treatment is probably not possession – remembering that those who had demons who were brought to Jesus had been seen by others, this was not something they had just developed but something they had struggled with for years. One thing I have not mentioned is what we should do to remove a demon, because I do not know much about this. I leave you with the words of a book I am reading:
The cure for demonic possession was faith in the power of Christ. Never were magic or rituals used to deliver one from demonic possession. The exorcisms of Jesus show His power over Satan and his demons. The Beelzebul passages (Matt. 12:25–29; Mark 3:23–27; Luke 11:17–22) demonstrate the presence of the kingdom of God in the present world order (Luke 11:20). The exorcisms of Jesus were accomplished by the power of His speech. He issued simple commands, such as “be quiet, and come out of him!” (Mark 1:25), or “you mute and deaf spirit, I command you: come out of him and never enter him again!” (Mark 9:25 HCSB). The disciples were given Christ’s authority and cast out demons (Luke 10:17–20; Acts 16:18). This success led Jewish exorcists to include the names of Jesus and Paul in their rituals (Acts 19:13). Despite Christ’s authority over demons, the Gospels portray a continuing battle in the present age (Matt. 13:36–49). The final outcome of the battle is not in doubt. The fate of Satan and his demonic hoard is assured (Rev. 20:10). 
 Joe Hayes (Barrow-in-Furness, Pastor Joe Hayes, 2006) an interesting and reasonable book which can be purchased through Through the Roof Books.
 Cathey, J. (2003). Demonic Possession. In C. Brand, C. Draper, A. England, S. Bond, E. R. Clendenen & T. C. Butler (Eds.), Holman Illustrated Bible Dictionary (C. Brand, C. Draper, A. England, S. Bond, E. R. Clendenen & T. C. Butler, Ed.) (412). Nashville, TN: Holman Bible Publishers.
- Week of the Darkness versus the Light: Exorcisms (theologyinbrief.wordpress.com)
- Poll: Most Republicans believe in demonic possession (salon.com)
- Things that go bump in the night (minkyweasel.com)