Снова с кворы.
I have been contacted to perform exorcism seven times and performed exactly one. Why only once, when six other cases were brought to me? Because not every situation is the result of a possessing spirit. The other cases involved medical conditions, mental illness, and in one, severe superstition on the part of the family requesting it. (The potential subject of the exorcism neither needed nor wanted the ritual.)
In my priestly role, there are a few things I do before any exorcism is performed:
If, by these examinations I've determined the cause might be spirit related, I then proceed on to a general blessing and cleansing of the subject. If the subject responds favourably to this, and I see no evidence of spirit possession, the process may be over. Or I may return to perform additional cleansing/blessing to remove any spiritually negative influences.
If, however, during the blessing and cleansing of the subject, evidence of a possessing spirit -- this can be direct communication with said spirit, or indirect evidence such as poltergeist-like activity, injury to the subject not explainable by natural means, manifestations of spirits, etc. -- then I will proceed to the exorcism.
That involves trying to identify the possessing spirit, what drew it to the subject, and what it's purpose for remaining is. When I can determine some or all of these things, I proceed with the ritual, which involves creating a holy space around the subject, ordering the possessing spirit out under the authority of whatever aspect of the divine the subject believes in, and in general making the environment unwelcoming for that spirit.
Even once the possessing spirit is cast out, it's important to take precautions against its return. If it was something the subject or those close to them were doing that attracted the spirit, I take measures to encourage that practice to stop. I ward the house with various amulets and talismans as well.
In the one case where I determined that exorcism was required, the subject them self was not at fault. Rather it was their Aunt, who was into various Spiritualism practices and had been rather casually communicating with various spirits for months before the subject began to show signs of possession. She did not ward herself when she did this, and further, "invited all interested spirits" to come and communicate.
The subject, had no history of mental illness or other medical conditions that might explain it, nor did other family members. Evidence included poltergeist-like activity and visible manifestations of spirits, which even casual visitors to the house experienced. The subject was also a well adjusted, functioning member of society before experiencing this.
The subject was non-violent, but would go into an almost hypnotic state when these things occurred, and could not communicate for up to an hour after the activity ceased. The spirit(s) appeared to be using the subject as a medium to manifest. (Why they did not use the Aunt, who invited them in the first place -- well your guess is as good as mine.)Immediately after the blessing and cleansing was the time I saw the most activity.
The ritual was successful in ending the activity and the subject's subsequent state, and the Aunt was convinced to leave off spirit communication and remove from the house the items related to the practice. As far as I am aware, there is no activity in the house today, and the subject has gone back to their regular lifestyle.
It's the only situation I've ever found that I felt the evidence was certain enough to warrant an exorcism, because I myself experienced some of these phenomena, and after a thorough investigation, I couldn't find a natural cause or any deception on the part of the subject or others.
In my experience, true cases of possession are rare and serious matters, not to be taken lightly.