The interesting thing about beliefs that significantly affect our lives is that it is almost impossible to evaluate them with rational thought or logic.
There is a very old story related to this by Abraham Maslow. The mental patient, who believed that he was dead in the mental hospital where he was admitted, and therefore did not participate in any vital activities, including eating, could not be convinced that he was not dead despite all the efforts made by all specialists psychiatrists. One of the psychiatrists, who understands that the patient will not give up on this decision and undertakes his treatment, finally poses a question to the patient about whether the dead can bleed. The patient answers this question, “Of course, it does not bleed, because all bodily functions of the dead have stopped.” The psychiatrist then takes a small needle and sticks it into the patient’s finger. The reaction of the patient, who looked at his finger in surprise for a while and saw that it was bleeding, was quite interesting: “Damn… the dead bleed too.”
Robert Dilts – “Sleight of Mouth: The Magic of Conversational Belief Change”