Men and women are, in various ways, subject to the influence of evil spirits. Virtually all cultures and schools of religious thought admit the possibility of a person being influenced by a demon, and demonic possession is a topic clearly addressed in the New Testament. Jesus appealed to His power over demons as one of the recognized signs of Messiahship (Matthew 12:23, 28; Luke 11:20). He cast out demons.
Still, as thinking persons of the 21st century, our first question must be:
Or to put the question a different way: Is demonic possession an objective reality, or a psychological problem? Do demons really exist, or are they all in the mind? Historically, demonic possession has been accepted and treated as reality-based. To quote Tertullian, "Let a person be brought before your tribunals who is plainly under demoniacal possession. The wicked spirit, bidden speak by the followers of Christ will as readily make the truthful confession that he is a demon as elsewhere he has falsely asserted that he is a god.....What clearer proof than a work like that? What more trustworthy than such a proof? The simplicity of truth is thus set forth: its own worth sustains it; no ground remains for the least suspicion. Do you say that it is done by magic or by some trick of the sort? You will not say anything of the sort if you have been allowed the use of your ears and eyes. For what argument can you bring against a thing that is exhibited to the eye in its naked reality?"
There is no question that a person with psychological problems may believe, falsely, that he or she is possessed by demons; but this fact does not in any way negate the possibility that someone without psychological issues may indeed be the victim of demon possession.
The best means of protecting oneself from demonic possession are:
If a person believes that he or she may be suffering from demonic possession, he or she should do three things:
In extreme cases, an exorcism may be warranted. According to the Catholic Encyclopedia, "Exorcism is (1) the act of driving out, or warding off, demons, or evil spirits, from persons, places, or things, which are believed to be possessed or infested by them, or are liable to become victims or instruments of their malice; (2) the means employed for this purpose, especially the solemn and authoritative adjuration of the demon, in the name of God, or any of the higher power in which he is subject."