O Timothy, keep that which is committed to thy trust, avoiding profane and vain babblings, and oppositions of science falsely so called. –1 Timothy 6:20 (KJV)
Night and day among the tombs and in the hills he would cry out and cut himself with stones. –Mark 5:5
“Does Job fear God for nothing?” Satan replied. 10 “Have you not put a hedge around him and his household and everything he has? You have blessed the work of his hands, so that his flocks and herds are spread throughout the land. 11 But now stretch out your hand and strike everything he has, and he will surely curse you to your face.” 12 The Lord said to Satan, “Very well, then, everything he has is in your power, but on the man himself do not lay a finger.” Then Satan went out from the presence of the Lord. –Job 1:9-12
God hath not given us the spirit of fear; but of power, and of love, and of a sound mind. –2 Timothy 1:7 (KJV)
The Comforter, which is the Holy Ghost. –John 14:26 (KJV)
The peace of God, which transcends all understanding, will guard your hearts and your minds in Christ Jesus. –Philippians 4:7
(1480-90)
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Etzel Cardeña, Varieties of Anomalous Experience, ch. 3: “Hallucinatory Experiences.”
Francis MacNutt, Deliverance from Evil Spirits, ch. 3.
Gabriele Amorth, An Exorcist Tells His Story, “The Point of Departure,” p. 67ff.
John Wimber, Power Healing, ch. 6, Appendix B: “Healing Those in Hospitals.”
WesleyGospel Ministries 
I can chime in here. I got schizophrenia when I was 17 (43 now). I didn’t take medication at first because I somehow thought I was ok. But about a year later I got a panic attack. They started happening more and more frequently so I was forced to take medication really. Now, as to whether that level of fear is demonic, I suspect it could be but it’s hard to say because the brain can go wrong too. Or perhaps what might start out as demonic can derange the physical brain and so it becomes difficult to separate the two. However, I never heard voices in my head or had hallucinations, it was more like a wonky belief system or delusional belief system. But I started to practice meditation and sought out psychics to try to understand what was wrong with me and to look for answers, for God. I would sometimes wake up out of sleep during that time and it seemed like inside there were negative voices that I was responding to inwardly, they were trying to torment me and laughing etc, and I would somehow kind of fight back against them. I never really thought much of that at the time, but looking back it seems clear I was demon possessed. I know that because when I was saved later by God I actually saw the demonic entities with my open eyes, they were like those dark black shadow entities and they were evicted from my body and yet it seemed they were attempting to re-enter but they couldn’t. However, that didn’t stop them from having access to my mind in different ways, as they would try to attack me with inner voices again when I tried to sleep. Sometimes they would flash images into my mind of half human half animal looking forms and faces, or ghoulish looking figures.
I would hear things like “Kill yourself” etc. That definitely wasn’t my own mental voice! I had no desire to kill myself. But because of ongoing usage of marijuana (which seemed to contribute to making me mentally ill in the first place) I believe I have been opening doors to these negative entities. I would and still do feel panic inside after I smoke a joint, but because I drink too that cancels out the bad effects of the pot at roughly the same time and I use both to cope. I believe that the pot usage attracts demons who can even work through other humans by making car noise near my house and in their behaviours sometimes when I go out to the shop etc. But the really really interesting thing I found was that if I wear a cross necklace all the time and mainly for protection while I sleep, the demonic attacks during sleep have almost disappeared completely! Due to having had some surgery I had to forgo drinking which meant I didn’t smoke either, and that particular night as I was lying in bed before I fell asleep, I heard a voice inside that said something like, “the cross cannot stop us” and this entity was very powerful and evil it seemed. It could have been the ringleader. Because they other attacks diminished in intensity. Shortly after that experience, there were no more nightly attacks.
About the idea that schizophrenics need to relax, that is CERTAINLY true in my case. I can testify to that. And lastly, when God saved me, I had visionary type experiences and never in my life before or since, so I know 100% for certain that that was not what a naturalist skeptic would call an “hallucination”. When the Society for Psychical Research first began around the 1870s or 1890s, they catalogued psychic experiences and used the term “hallucination” to refer to real genuine spiritual experiences. Later, that was co-opted to refer to abnormal mental states.
David, thank you for sharing about this. Its extremely helpful. There is no question that your experience, and the experience of thousands of others under the influence of schizophrenia, have proven the existence of demons as real objective spiritual entities with intelligence; and that they are not simply metaphors of evil in our hearts. In a way, schizophrenia supports what the Gospels say about the existence of the devil.
For the sake of others reading here, I would only recommend psychiatric drugs under the care of a psychiatrist, an occasional wine cooler, prayer, contemplation, and charismatic worship as stress relievers. Removal from dysfunctional families and finding genuine love with a Christian spouse. All of these things are healthy, relaxing, and conducive to living in peace. But I would avoid getting drunk and high; and avoid marijuana products. These things are addictive, and can have a rubber band effect, and fling you back into an anxiety state with withdrawal cravings: and the devil’s voice might come back in those times.
Absolutely I don’t recommend marijuana or alcohol for those prone to serious mental illness and it’s important to see a qualified psychiatrist. Due to contact with a person who helped me towards getting saved who said I should come off of medication, I did and I relapsed really seriously badly. It’s taken around 6 years to return to normal upon taking medication again. It’s extremely important to talk to doctors where mental ill is concerned and not listen to laypersons, even if they are Christians.