Question: Jesus' healings in Matthew 23-25 appear to be separated into different categories but under one heading, "all sick people." The problems are listed: "divers diseases...torments...those possessed with devils...those which were lunatick, etc. What is "lunatick"? Does it refer to a medical, or mental problem?
Response: The different categories have no significance except to show that all were healed who came to Christ.
The word "lunatick" occurs only twice in the Bible, both in Matthew:4:24 and Matthew:17:15. It is the same as our word, lunatic, which means insane. In Matthew:4:24, there seems to be no demonic involvement because "lunatick" is distinguished from "those which were possessed with devils." The Bible indicates that one can become irrational due to wrong thoughts, imaginations, jealousy, etc., and we are told to "bring every thought into captivity to the obedience of Christ" (2 Corinthians:10:3-6). Yet in Matthew:17:15, it is made very clear that the "lunatick" in this case was demon possessed because "Jesus rebuked the devil; and he departed out of him."
We are not dealing here with a medical diagnosis, because science cannot discern demonic possession. These verses would lead one to conclude that there probably are many persons today diagnosed as insane who will spend the rest of their days in a heavily medicated stupor, when all the time the problem is demon possession and they need spiritual deliverance.
Unfortunately, a psychiatric hospital would not look with favor upon a Christian, even a close relative, coming in to cast a demon or demons out of a patient. In fact, such a person would be prevented from any contact with the patient.