Exorcism is a skilled practice, and the methods to evict a demon have developed through many centuries of observation and practice by the religious faithful or spiritual leaders. Since recorded history, religious denominations and spiritually in-tune clairvoyants have sought to lead the battle against demonic possession. However, the challenge for many is the ability to recognize whether a demonic presence actually possess a person, or whether that person, instead, suffers from an undiagnosed mental illness.
The International Association of Exorcists meets twice a year in Rome. While they do not publish their statutes, which outline the criteria for determining whether a demon genuinely possesses a human being, they do provide legitimacy to the battle between sanity, goodness, and the fiendish demons in their various forms that, according to the association, seek to assume our bodies and dominate our minds.
Should a person become possessed by a demonic presence, it's of critical importance that an individual skilled in exorcism assist in expelling the monster. However, just like the International Association of Exorcists, it's important to first determine whether the person in question legitimately does have a demon inside them before any attempts at an exorcism.
If a demon wishes to possess a person, it will command that person's entire being. Accordingly, demons do not like it when the religious or spiritual attempt to evict them. A person who is possessed by a demonic presence will act harshly if a person prays in their presence for a prolonged period.
If after the extended period of prayer, the suspected possessed begins to blaspheme and curse god, a demon is likely inside that person.
Demons are not people, but they do like people. They like to possess them. So, any witchcraft-like endeavors, or magic show attendance, will likely get a demon's attention. When a person engages in activities like conjuring the dead, using an Ouija board, or reaching out to a spiritualist, that person is, (basically), giving a demon the green light an invitation to possess their mind, body, and soul.
When analyzing whether or not a person is suffering from demonic possession, it's not enough for someone to just look gothic or dress in black. When an evil spirit controls a person, the eyes of the human capsule turn black.
It's not just the pupil that turns black, a possessed person's pupil, iris, cornea, and lens, will all darken, and the demon-person's face will look like a hallowed out jack-o-lantern without a candle.
Most people who get possessed by a demon experience acute and rapid dental decay. Additionally, newer, longer, sharper, and grayer teeth begin to erupt from the possessed person's mouth, sometimes causing bleeding, but almost always resulting in a facial paralysis that does not allow the mouth to fully close.