Once in a retreat with a Sufi master in San Francisco, he defined the Sufis as follows: They started as a group of true seekers a few hundred years ago, and they personally tested all spiritual techniques known. Those that worked they kept, those that not they discarded. This practical approach resulted in the Sufis! The whole day we performed a huge set of those techniques... at the end all I saw was light - a white light - and peace -- everywhere ...