The following articles have been compiled and indexed by inWORD Bible software.
What Are Demons?
To “have a demon” was the same as to “have an unclean spirit”, which is a Bible way of saying that something was wrong or “unclean” about a person’s way of thinking or mental capability. In short, a person with a demon was a person with a mental illness.
Note on Diabolical Possession
In the New Testament, disease, except when it is a special visitation from God (Hebrews 12:6), is regarded as the work of super-natural forces (Matthew 9:32, 12:22; Luke 11:14, 13:16; Acts 10:38, etc.). In particular, nervous diseases and insanity are represented as due to diabolical possession. This was the universal belief of the time, and our Lord, in using language which implies it, need not be regarded as teaching dogmatically that there is such a thing as possession, devils or demons. There were strong reasons why He should seek to ‘accommodate’ his language to the popular theory. (1) The insane persons whom He wished to heal, were firmly convinced that they were possessed by devils. This was the form assumed by the insane delusion, and to argue against it was useless. The only wise course was to assume that the unclean spirit was there, and to command it to come forth. (2) It was our Lord’s method not rashly or unnecessarily to interfere with the settled beliefs of his time, or to anticipate the discoveries of modern science. The belief in demonic possession, though probably erroneous, was so near the truth, that for most purposes of practical religion it might be regarded as true. He, therefore, did not think fit to disturb it. He tolerated the belief and left it to the advance of knowledge in future ages to correct the extravagances connected with it.
The Language of Accommodation
John Walton said it particularly well in a lecture: “Nowhere in the Bible does God ever ‘upgrade’ the Israelites’ understanding of the world.” Meaning: He doesn’t tell them the world is a sphere; He doesn’t tell them that the sun is bigger than the earth or that most stars are bigger than the sun. He doesn’t expound the germ theory of disease. He doesn’t explain the causes of mental illness. He doesn’t give them any new technology—including steam engines, but also including, say, soap; etc., etc. He takes them as He finds them, and expounds to them theological ideas only.