It has occurred to me that the brotherhoods and fellowship circles that developed among Russian-German Lutherans, Mennonites and Baptists in Kazakhstan in the 40s and 50s resemble sufi brotherhoods. More specifically they appear to have been formed for the same reasons and filled the same social function as the Chechen sufi brotherhoods. The fact they were both formed at roughly the same time by deportees in Kazakhstan adds weight to this observation.
In both cases communities of faith adapted to survive severe repression. Repression that was based both upon their ethnicity and religious beliefs. These adaptations are not unique to the USSR. Early Christians in the Roman Empire also organized informal and underground circles of believers to maintain their communal religious existence. Suffism has a long history of being adopted by Muslims of many different nationalities as a way of resisiting foreign oppression. Sufis have been associated with anti-colonial movments in places as diverse as the Caucasus, West Africa and Indonesia. The clandestine meeting of lay believers to maintain their traditions of worship by Russian-Germans and Chechens kept their communities alive despite the annihilation of formal religious infrastructures including Lutheran pastors and the ulema. The Catholic Church with its reliance upon trained and ordained clergy in a specific heirarchy found it much more difficult to adapt in exile. The belief of a personal relationship with God and a priesthood of all believers by the pietically influenced Russian-German Lutherans, Mennonites and Baptists proved more durable. Especially as the various brotherhoods moved closer to the organization of the Mennonite Brethren under the pressures of exile. Likewise Muslims also believe in a personal relationship with God and the Umma is a community not a flock. Of all the Abrahamic religions Islam has prehaps proved the most flexible in surviving in hostile surroundings due to this non-hierarchial structure. It is probably thus not surprising that under extreme pressure that Christian practices among the Russian-Germans came to more closely resemble Islamic ones.