:The phrase "suddenly in the synagogue" does not in the Greek text of Mark mean that the man suddenly entered. The structure of Greek syntax here indicates that the man in the synagogue suddenly made the verbal outburst, a behavior which the congregation did not expect. This man who seemed to be normal, immediately perceived who Jesus is, and he reacted strongly. (Compare [http://biblehub.com/commentaries/mark/1-23.htm various commentaries on Mark 1:23].)
:'''[[Judas Iscariot]]''' is an example of someone whom '''Satan <big>I</big>tself''' entered (''spirit-beings have no gender''), and yet Judas acted like a normal person, Luke 22:3-6; John 13:26-29. John himself comments that Jesus had already indirectly indicated that Judas was "a devil", and that he was "a thief" who actually cared nothing for the poor, John 6:71; 12:4-6.<br>Similarly, Ananias' heart was filled with Satan, but he too acted like a normal person, Acts 5:3.
:Seemingly normal people who usually appear to simply regard the moral content of genuine religious practice and devotion to God with sneering contempt and disdain while still professing to be regular members of the religious faith-based community ([[denomination]]), '''''are occasionally, in some very few cases''''', suddenly and unexpectedly found to be undeniably afflicted with evil spirits, who loathe goodness and piety—who sometimes even [[paradox]]ically characterize with verbal jibes all [[corporal and spiritual works of mercy]] as being at their very root ''probably'' acts "''of the devil''" (compare Matthew 12:22-37). These unhappy individuals normally seem somewhat unnaturally devoid of any degree of ordinary tender compassion and mercy toward others, rather unforgiving, sternly practical, coolly professing to have only ordinary [[common sense]], even while they are generally polite in a conventional sense in public toward casual acquaintances, business associates (if any) and their own social circle of occasional friends who admittedly confess they don't know them very well. They are not always persons who can be characterized in general as people of ill-will, or as being totally unsympathetic. Even leaders of [[organized crime]] love those who love them, to a certain extent. (See Luke 6:32-34; Matthew 5:46-47.)
:Complicating the issue are two different situations:
:*those cases of desperate attention-getters who subconsciously seek to be the intense focus of a dramatic public exorcism who are not in fact possessed, who may ''or may not'' be mentally ill, and
:*those carefully documented cases which have repeatedly and conclusively demonstrated the fact that many persons who actually do harbor evil spirits are usually unaware of it before conclusive evidence of its presence is discovered, and in some cases the reality that the evil spirit inhabiting the victim does not always seize complete control of the victim's body causing a complete loss of conscious awareness, but can take involuntary control of parts of the victim's body against their will—for example, partial paralysis of limbs, intermittent episodes of partial blindness or complete and permanent blindness, deafness, speech impairment, rashes, peculiar skin eruptions, boils, fevers, chills, involuntary spasmodic movements, unexplainable disabilities resulting in unemployment or ability to care for oneself, all without any apparent physiological origin or ordinarily diagnosable observable pathology according to nature. Job 2:7; Exodus 12:23; Luke 13:11 and 16; 1 Timothy 1:20 and 1 Corinthians 5:5; 10:10; Mark 1:26; 3:10-11; 5:2-5 and 8; Mark 9:20-27; Matthew 12:43; Acts 16:16; Acts 19:16; Luke 6:18; 7:21—compare the experience of Saul king of Israel, 1 Samuel 16:14-16 and 23; 18:10-11; 28:3-13; also Saul's behavior 1 Samuel 18:6-29; 19:9-15; 22:11-19; 24:16-17.
:Careful research of case after case of proven demonic possession has demonstrated that evil spirits cannot actually touch the personal will of their victims. The invisible oppressing spirit has made itself a constant companion. The victim is like a city under siege. Possession can take the form of unrelenting depression or obsession without evidence of any physical [[Genetics|genetic]] or [[pathogen]]ic origin, and never feature episodes of bizarre or suddenly unexpected speech and behavior which superficially resemble [[Schizoid personality disorder]], [[Tourette's syndrome]] or [[Epilepsy|epileptic siezures]]. Many victims of oppression by evil spirits are afflicted with unrelieved anxiety, dread, inexplicable feelings of intense guilt, sensations of impending catastrophe, fears of contamination, restless activity, or continuous agitation over endless projects which deprive the victim of adequate sleep and healthy social interaction, all of which are unfocused, generalized, without discernable cause or reason, and which are persistently and mysteriously unresponsive to aggressive medical treatment and probing in-depth counselling, but are undramatic cases of suffering which do not in any way present episodes of inexplicable speech and bizarre behaviors of the kind made infamous by sensation-seeking novels and films about evil demonic entities and demonic possession as forms of "entertainment" (for example, William Peter Blatty's, ''[[The Exorcist]]'', and [https://en.wikipedia.org/wiki/The_Rite_%282011_film%29 ''The Rite'' (2011)], starring Anthony Hopkins, based on Matt Baglio's factual book ''The Rite: The Making of a Modern Exorcist'').