Dr Aamer al-Hadithi, a film producer and university professor whom I met at the Qadiri mosque, explained:
"Islam - submission - is the essence of religion. Islam means submitting yourself to God. The Christian must submit himself to God. The Jew must submit himself to God. The prophets brought one model for worship - the commandments and punishments and so on are all the same. But God ordered that we should talk to people in a way they could understand, because every time and place has its appropriate means.
"God is Lord of the world and those who live in it, God of time and place, and he doesn't talk to me in a language that can't be understood by someone living in this century."
So does everyone who joins the Order have to be a Muslim?
"We have people from different religions in the Order, but they have to believe in the way of the Order. The way of the Order is that you must believe in all the prophets, you must believe in Our Master Mohammed, the seal of the prophets. Anyone who believes this is a follower of the Order. We are not concerned with names. We say that the names were created by human beings."