I still vividly remember one of my early seminary colloquia in the NT theology. Our New Testament professor was an internationally recognized scholar and that day he challenged us to take seriously the biblical world-view teeming with demons.
At first, we students wanted to dismiss it as an outdated superstition. He agreed with us that demons were part of the ancient mythological world-view but he also wanted us to approach it more creatively. He pointed out that ancient people were not stupid, they were just as intelligent as we are. They perhaps did not have modern laboratories, and modern science, but they were keen observers. They experienced rapidly spreading infections and they quite correctly surmised an influence of some kind of invisible agents which were hopping from one person to another. They called them demons while these days we called them bacteria and viruses.
But he went further and talked about demons causing what we would call mental illnesses. In that instance our professor quoted his wife, a clinical psychologist, and soon to be a psychology professor at the Charles University. He proposed to us that the world-view with demons responsible for mental illnesses was in fact very benevolent, gentle, kind and gracious.
That ancient perspective was benevolent because it allowed a clear distinction between the person and the demon. The possessed person was not evil to the core, evil behavior was caused by the demon which controlled him or her. Only the fully developed and most mature psychology, psychiatry, and sociology were able to reach this level of insight, sophistication and humanity recognizing influences of environment, physiology, family history, and personal or societal trauma.
I am thankful to my professor for this lesson, for showing us this example of constructive Bultmanian demythologisation, this respectful interpretation of an ancient world-view.
We do not need to truly believe in demons or engage in magical exorcisms to appreciate their deeper and still relevant lessons leading us to a more humane way about illness and people in distress.