Faith healing

Faith healing refers to the healing of diseases, infirmities, etc., by supernatural means. In modern times, many Christian evangelists have claimed to have this ability. Some Christians have cited them as powerful evidence for the existence of God and the truth of Christianity. However, investigations of faith healers by men such as doctor William Nolen and magician James Randi have failed to find any evidence of actual miracles, and have turned up much evidence of fraud or, at best, self-deception.

Methods
The methods by which faith healers convince others of their powers can be divided into two groups: those that do not require conscious trickery on the part of the healer and those that do.

Without trickery
In his investigation of Kathryn Kuhlman, Nolen came to the conclusion that she was probably sincere. His observations of her patients suggest a number of ways in which a healer could come to falsely believe in his or her powers:
 * One man got up out of a wheelchair, but having met the man earlier, Nolen knew he had merely found walking difficult, not impossible. The man was back in his wheelchair after the service.
 * One 20-year old girl came up on stage to claim a cure for polio, but as a doctor Nolen could see that she was obviously not cured. However, both Kuhlman and her audience seemed equally oblivious to this fact.
 * Follow ups of patients with diseases that can improve naturally, such as multiple sclerosis, migraines, and bursitis resulted in patients claiming cures based on improvement but not total recovery, and even the extent of the improvement was unclear.
 * Follow ups of patients who had claimed cures for cancer found that they all still had cancer afterwards, and in at least two cases the patient died shortly after visiting Kuhlman.

In summarizing his investigation, Nolen concluded: "The problem is, and I'm sorry this has to be so blunt, one of ignorance. Miss Kuhlman doesn't know the difference between psychogenic and organic diseases; she doesn't know anything about hypnotism and the power of suggestion; she doesn't know anything about the autonomic nervous system."

Thus, her lack of knowledge prevented her from accurately assessing what was going on in the people who came to her for help.

Involving trickery
One of the main types of deception used by faith healers is faking miraculous knowledge of the ailments people come to them for. This can be done by having people write down their ailments on sealed slips whose contents are revealed using a standard magician's trick known as the "one ahead trick." It can also be done by having assistants pump clients for information, which the healer may then commit to memory, put into notes, or be delivered by a secret radio receiver. The latter was the method used by Peter Popoff, whom James Randi exposed by using an electronic eavesdropping system to record the radio messages. This recording was then played over a tape of one of Popoff's performances on Johnny Carson's Tonight Show.

Another common trick is known as leg-lengthening, where the healer claims the patient has one leg longer than the other and then purports to correct the problem right before the audience's eyes. To those not familiar with the trick, it can seem like an undeniable miracle, but it is in fact a variant of a standard carnival trick and is explained in great detail in James Randi's book The Faith Healers.