http://www.nightwatchmanchronicles.com/INT/DianaPossession.htm
In a recent poll conducted by America Online, participants were asked the question, "Do you believe demonic possession happens?" 72% said they do believe possession happens and only a mere 28% of people polled said they didn't believe demonic possession happens.
In Rome, there is a four-month course called "Exorcism and Prayer of Liberation" which is run by a Vatican university for aspiring demonologists and exorcists. In this course, students hear lectures on topics ranging from pastoral, spiritual, theological and liturgical aspects to medical, legal and criminological aspects of Satanism and demonic possession.
A demon, in conventional thought, is an entity of pure malevolence. Essentially, a demon is an element of evil consisting of Satan and his many minions. One similarity in demons among several cultures that embrace Christianity is the origin of the "head demon" which is Satan. In actuality, demons are fallen angels of the Celestial Order. These demons personify evil, pain and suffering. A demon exploits a specific weakness in a person, creates a certain suffering for a person, or wants something from a person.
Diabolic activity generally falls into three categories. Infestation, Oppression and Possession. The first, infestation, refers to those people who are harassed by a diabolic entity inside their homes. Oppression is worse. It's when an external attack occurs on a certain person. The entity will cause fatigue, depression, weariness and it can put on "shows" to frighten the person, such as shaking a person's bed at night while sleeping, verbally assaulting them or appearing to them in a frightening manner. The rarest and most serious of the three categories is possession. There is partial and full possession. Partial possession means a certain part of the body. Full possession means the entity takes full control of the person's body.
To combat demonic activity, there are three types of exorcisms that can be performed. The first is liturgical. The second is a private or simple exorcism in which any one of faith can order the entity to "be gone." The third is a "public" or formal exorcism. This type may only be carried out with authorization of a bishop and it may have to be repeated more than once.
In a recent case in which a homeowner had been plagued by demonic activity for the better part of 20 years, he asked, "Why do demons pick a particular person or place and stay for so long?"
The answer is not easy to explain. If you consider that there are millions and millions of people on this planet that never experience this type of phenomena, it tells you that there is a selection process that takes place. That being said, what makes a good "target"? Four things are to be considered.
1. The person or persons themselves.
2. The dwelling that they seek to possess as their own
3. The risk of being expelled or ousted.
4. Physical objects being brought into the home.
If you break the above four down, it goes like this:
1) Is there someone in the home that's opening the door? Did they use a Ouija board, and in effect, stick their hand blindly into the spirit realm? When that is done incorrectly, the hand can be latched onto by the wrong side. They could be practicing witchcraft or sorcery or worshipping gods other than the Creator? Are they committing acts that would be considered vile or criminal? Or, it could be a simple attraction by a demon that is attracted to a female living in a residence. Or, perhaps it's a female legionnaire that is attracted to a male living in a residence. They can also be brought back with someone from somewhere else. The person might have gone somewhere and were consequently followed back. Or, they could have been sent one by an agent of Satan. It might be from the top rung of the ladder, or all the way down to the bottom rung of the ladder and an all out hooded devil worshiper.
Maybe they are offended, or seeking to cause the person problems so they can move up in a job; or any number of reasons in which they might use Black Magic against them. Demons can also simply take a dislike to certain people. The person might have said something one heard and did not like. They (the demons) are like people. If they take a dislike to someone, it gets personal with them. They will remain where that person is and stay until they are either ousted or the person passes over.
2) Demons, many of them, want to be back on Earth as humans. At least those from the Biblical pre-flood days. They might try and fool you into thinking they are ghosts. Or, they might just harass you. Like Cosby said in an episode, "The kids want the house!" The demons might want your dwelling. It's rare, but it happens. Sometimes they also stay where a person has died. It might have been a murder, or suicide, or just a normal passing. But they seek to fool people into believing they are that person. And some demons are lunatics - just like some people are. They will try to drive people insane because those demons hate humans. They blame them for the Judgment hanging over their heads. They seek revenge.
3) If the risk is low of being expelled, exorcised - ousted or whatever else might happen that would cause them to have to leave, then that dwelling is a safe bet to inhabit. There is sometimes no rhyme or reason for them picking certain individuals. But to correctly assess why they might have come there in the first place, all factors must be taken into account. If all else fails, it was a draw of the deck. The person's card got picked by pure chance.
4) Lastly, there is the chance of physical objects having demons attached to them. They consider that object their own. If you buy it, or someone gives it to you, the demon or demons go with it. If you destroy it, you are in BIG trouble with those demons. And concerning these types of demons, Satan considered them the most unruly of his lot. They want to do what they want to do, not what they are told. So, many times Satan lets them go their way. They still add fuel to his myths of demons being powerful. But, Satan has the power to pull them to him. Satan actually is less in power than he likes people to believe, but he's more powerful than his confederates.
The most important thing to know when faced with having to combat demons is that it's fear that is the most powerful weapon Satan and his demons possess. Coupled with the belief that demons can do harm to you and you are in for trouble.
In so many cases in which you read about demonic activity, those being harassed become afraid of the dark because they fear the evil they believe lurks there. In reality, that evil is present even in the daylight. But the very belief that they feel they are vulnerable is what gives the demons the opening they need to harass someone. To combat them, that fear should be shut out. But, there is healthy fear also. It is fear generated from the natural instinct to survive. For example, you hear a window shattered in the middle of the night. That fear that you feel is for your safety. That is the difference. It is a different kind of fear. The other fear is generated by the mind, and it is a fear of the unknown of the spiritual world. That is the fear that Satan and his demons are permitted to work off of. It is not a healthy fear. It's detrimental.
Something else about this type of fear is that the demons can literally smell it. It is their cue that a person's mind's door is open to attack. Under the Creator's Rules, it gives them the right to enter your presence of mind. During that period, they can and will test you. It can be lengthy, which is why it's so important to shut out that type of fear. Don't provide the very thing the demons can and will use against you. The fact that Satan is powerful, but limited as to how he can use those powers, gives reason enough to keep the door closed to him. With the door closed, he is powerless; otherwise, he is very powerful.
It is best for a person under attack to do their own prayer for help. Whether intervention will help to end the demonic attack is determined by many factors.