We tend only to believe what we can see, and what we see is always filtered by our personal perception. Take the example of a man who is already extremely paranoid about imaginary problems and firmly believes he has ghostly tenants living in his cupboard. To tell such a person that the ghosts are a figment of his imagination will not help him at all because he is quite certain that ghosts exist. A far less time-consuming and more efficient approach would be to agree skillfully that in a way his paranoid delusion is real, and then offer a method for dispelling that delusion — such as calling in the Ghostbusters!
Dzongsar Khyentse Rinpoche