Yes this has been done in different ways by different photographers. The first one that comes to mind is the Amish work that George Tice made mostly in the '60s. Another photographer Laura Wilson (Avedon's former assistant) spent many years documenting the Hutterites of Montana and published a book by the same name. Other photographers have done books or portfolios of various cult type relegious groups like Baptist snake handlers and small southern black Baptist chruches and their members, though I can't recall their names now.
Originally Posted by mark
Chris Ranier has also done work with different cultures around the world whose subjects and environments usually have some religous associations.