Evil spirits possess the victim . Alcoholism is seen as a weakness, mental illness is seen as irresponsibility, criminal and deviant acts result from giving in to our evil nature , sexual deviance is seen as moral depravity, and rebellion is seen as immaturity. In each case the cause of deviance lies within the individual. It is easy to blame individuals. Societal-based problems are difficult to understand and even more difficult to correct.
People seem to prefer what is easiest.
Even today, people have trouble understanding that the cause of conditions they do not like may, in fact, be social in origin. Solutions used to correct demonic possession seems bazaar. Holes were drilled in the head of hosts to let the evil spirits escape. Exorcisms were also employed. Demonic possession lost it popularity around the 1700s.