Exorcism, which comes from the Greek exorkosis, which means “out-oath,” is an attempt to evict demons or spirits from the body of a normally living human being. Technically, exorcism is not driving out the Devil or a demon, but it is placing the Devil or demon on oath.
Exorcism is based on the belief that demons are capable of possessing people. As long as such belief remains there will be belief that some people have power over those demons, forcing them to cease their possession.
Why should I be aware of this?
Apparently belief in demons and exorcism became really popular only in 1st century Judaism, with the Pharisees actively engaged in identifying and exorcising demons.
Exorcism of evil spirits, which is commonly associated with the ministry of Jesus, is making a comeback in Catholic regions of Europe. In July 2007, more than 300 practitioners gathered in the Polish city of Czestochowa for the fourth International Congress of Exorcists.
Revival of exorcism, it is felt, has been necessitated to counter an increase in people plagued by evil. Typical cases include people who turn away from the church and embrace new age therapies, alternative religions or the occult.
Treatment for a spiritual problem
Exorcism is considered as a treatment for a spiritual problem (e.g., demon possession) and is distinct from a mental or physical problem. If one has faith in the system of theological thought underlying the exorcism rite, then the distinction between the mental and spiritual is sound and the treatment is absolutely important, necessary and even precise. But if the belief is lacking, then the distinction collapses and the treatment is just another non-evidence-based folk remedy which might do more harm than good if mis-applied.
All about exorcism
This act of exorcism is based on the Scripture that the Devil, his demons, and evil spirits are afraid of Christ. The belief itself is based on Scripture. Not only did Christ exorcize demons, or unclean spirits, but he gave the powers to his disciples.
Both the Catholics and Protestants believe they have the power to cast out the Devils and to heal. The code of Cannon Law allows authorized ministers (the exorcists) to perform solemn exorcisms not only over the faithful, but also over non-Catholics and those who have been excommunicated from the Church.
By the mid-twentieth century exorcisms had been largely discarded as a symptom of past superstitions and were not generally encouraged by religious leaders. But lately there has been a revival and there is now a booming industry in exorcisms in the United States.
Types of exorcism
There are several types of exorcism in the Roman Catholic Church:
- Baptismal exorcism - blessing an infant prior to baptism to cleanse it of evil resulting from original sin
- Simple exorcism - blessing a place or thing to rid it of evil influence
- Real exorcism - performing the Rite of Exorcism to rid a human being of diabolical possession
According to the Church, telltale signs of demonic possession include:
- Speaking or understanding languages which the person has never learned (different from "speaking in tongues," which is considered a sign of religious ecstasy, not possession)
- Knowing (and revealing) things the person has no earthly way of knowing
- Physical strength beyond the person's natural physical makeup
- A violent aversion to God, the Virgin Mary, the cross and other images of Catholic faith. 
Exorcism in other religion
Exorcism is also practiced in other religions and cultures around the world all have their own way of "casting out the devil." Here are just a few examples:
A dybbuk, a malevolent spirit in Jewish folklore and Kabbalah teachings, is the soul of a dead person that comes back to address unfinished business, and it inhabits the body of a living person in order to carry out its goals. A rite of exorcism is done to expel the dybbuk which leaves the body through the toe.
In Islamic belief a jinn -- an evil spirit and servant of Satan -- can invade the human body and cause illness, pain, torment and evil thoughts. By reciting particular passages of the Qur'an this jinn can be expelled.
In Hinduism, the Vedas scriptures tell of an evil spirit that can not only harm humans, but can also stand in the way of the will of the gods. A traditional Hindu exorcism includes such rituals as burning pig excrement, reciting prayers and offering sweets to the Gods.
A controversy surrounding exorcisms exists mainly on two related fronts:
- Exorcism for Profit
With money entering the scene of exorcism many skeptics around the world found enough grounds to reject outright the Catholic view of possession and exorcism, even though the exorcisms performed by these unofficial exorcists are not in any way connected to the Catholic Church.
- Psychology vs. Religion
This is probably the greatest debate surrounding the practice of exorcism. Psychological disorders, including Tourette syndrome and schizophrenia, can produce the types of effects seen in "possessed" people. People with epilepsy can suddenly go into convulsions when having a seizure; Tourette syndrome causes involuntary movements and vocal outbursts; schizophrenia involves auditory and visual hallucinations, paranoia, delusions and sometimes violent behavior. Psychological issues like low self-esteem and narcissism can cause a person to act out the role of "possessed person" in order to gain attention. In a case where the subject is in fact suffering from mental illness, the Church is doing harm by labeling the person possessed if this prevents the person from seeking out the medical treatment he or she requires.