A pattern of behavior where a person in Jerusalem “acts out” in socially inappropriate ways, such as accosting people in public, sometimes in “Biblical” clothing, while actually believing themselves to be Elijah, or The Messiah, or One of the Two Witnesses, or A Prophet, or other such improbable Biblical character. Not to be mistaken for true ministers sharing the Love of YHWH on the streets and byways of Jerusalem.

Jerusalem syndrome is a phenomenon aware of people, pilgrims, tourists who come to Jerusalem are so overwhelmed by the sense of holiness here that something happens to them. And certain fantasies, redemption fantasies of making the world a better place overcome them, and they believe they have a messianic mission which they must fulfill, which can cause problems. And this can happen sometimes to people who showed no sign of any sort of mental illness before this. And more often it will happen to people who have already been diagnosed and have had problems with their adjustment before coming to Jerusalem.

– Dr. PESACH LICHTENBERG. Director, Division of Men’s Psychiatry, Herzog Hospital, Israel. (NPR.org)

The Jerusalem syndrome is a group of mental phenomena involving the presence of either religiously themed obsessive ideas, delusions or other psychosis-like experiences that are triggered by a visit to the city of Jerusalem. It is not endemic to one single religion or denomination but has affected Jews, Christians and Muslims of many different backgrounds.

(Wikipedia)