I am going to stick my oar in here. Although my label is Pentecostal, I am the session clerk in my local PCANZ church. I have been a member and elder of the Presbyterian Church since 1996, but have retained my Pentecostal theology. It has been a great learning experience for me and the group of good Presbyterian men who surround me have brought balance to my views and opinions. I also have a strong background in Puritan Calvinist theology as well which put me on the outer in some Arminian Pentecostal circles. So for that reason. the Presbyterian Church (In New Zealand it still observes the Westminster Confession as its guiding document beside the Bible) provides a good theological balance for me. I also have an M.Div from an accredited on-line Bible college in Lousiana, whose staff are affiliated to the Church of Christ. So you see, I am a bit of a mixture.
My view about demons is that they exist and are active in today's world. The devil is the god of this world, and has a multitude of demons to preside over nations, cities, churches, etc., and each have different functions and duties. They are ruled by fear, and if they fail at their job they are cruelly beaten. Their primary purpose in the world is to stop people coming to Christ. Once we understand that, then we understand what demons are about.
I don't believe in the world's popular view of demons as depicted in the movie "The Exorcist" or red ugly dragon like beings running around scaring people. Demons can possess people, but in most cases you would never know because demons don't like to advertise their presence. They will only manifest in a person when an affected person is being counselled by a Christian counsellor who exposes the infection through careful questioning about aspects of that persons life and conduct.
I don't believe in the practice of casting out of demons in public church services. Dealing with demons should be in private and with a fully trained and competent Christian counsellor who is trained in spiritual warfare.
Demons have complete control over people who have not received Christ as Saviour. They have no control over Christian believers. In fact, Christian believers have absolute authority over them and demons have to obey without question.
Demons have full control in Occult and New Age environments, and also in pagan environments when false gods are worshipped. People in third world countries such as Africa, Asia, and South America are more inclined to believe in demon activity than those in Western countries.
Demons usually just influence the thinking of people rather than possess or take full control of them. Some but not all mental health issues can be the influence of demons, especially when people hear strange voices in their heads, and are influenced to commit crimes or kill people for no reason. I believe that some of the mass shootings in American schools have been the result of demon influence. How else can such horrible crimes be explained?
Although I have given this account of demons. I do not believe that there is a demon under every bush, but like spiders and snakes which are not often seen. they are there.
These are just my opinions and you can take them or leave them. I don't mind if you want to debate, but I am not allowed to do that on this forum, so if you would like to do it on the Controversial Theology forum I will be very happy to take part.
Two good books that have taught me a lot about spiritual warfare and how to deal with bondage caused by the influence of demons are:
The Handbook of Spiritual Warfare by Dr Ed Murphy;
The Bondage Breaker by Dr Neil Anderson.
Both of these books take a private counselling approach. Dr Murphy's book traces the influence of demons right through the Old and New Testaments before he gets on to the practical aspects of how to deal with them.
I trust that my post has been helpful to some who might have been worried, concerned about, or fearful of the idea of demons.