Scripture speaks in a number of places of people who suffered severe physical affliction that did not have “natural” causes (e.g. unhealthy lifestyle, accidents, or advanced age):
—Job had no idea that his physical affliction was caused by Satan (Job 2:7).
—Luke provides no indication to us that the woman who had been crippled for 18 years knew that her infirmity was caused by Satan, but he does record that Jesus made known (after He had healed her) that it was (Luke 13:16).
—Herod “was eaten of worms” and died because the angel of the Lord had smitten him (Acts 12:23), but we have no indication that he knew of the supernatural cause of his fatal illness.
Given this data (and other related biblical teaching), it seems to me that we need to consider more often than we probably have been doing that the serious physical afflictions that some people suffer from may be the direct result of supernatural activity that they have been the objects of without their having any knowledge of such activity.