Why did God let people think demons cause epilepsy?

[Drich]

A question for Christians.

Exorcism of demons is mentioned in several Bible verses, and I know most Christians would say that's because demon possession is a real phenomenon. However, most Christians in developed nations no longer attribute all manner of diseases, especially neurological diseases like epilepsy and psychotic illnesses, to demons in the vast majority of cases. So presumably, most of you believe that most sufferers of such conditions who are having torturous and sometimes deadly exorcisms performed on them in Africa, by people pointing to Jesus' healing of demon-possessed people who were symptomatically indistinguishable from epileptics, are not possessed and should see doctors instead.

...Just because you can physically describe a process or an illness, does not remove the process or the tool from the demonic tool box.

So why did God allow verses like that to end up in the Bible without clarifying that a) it's not always demons (or the result of sin, a related belief about some illnesses that people get from the Bible)

What in the bible makes you think that it says all 'mental disorders' are the result of demons? I simple only ever points out cases where demons had possessed someone. And, again who is to say they could not use a mental disorder as a tool of that specific possession?

and b) if you must exorcise a demon, don't hurt the person. He knew toddlers would be getting tortured to death as a result of the miracles as they are described in the New Testament, right? 

Like before, what in the bible makes you assume that physical harm is apart of a proper excorsism? The examples in the bible are of a single command from Jesus or an apstole for the demon to leave.