Rodney Stark, noted sociologist of religion, has contended in a series of publications that Mormonism is well on its way to becoming a world religion. (Stark, The Rise of Mormonism, Columbia University Press.) Stark predicts their numbers will rival other world religions. Gerald McDermott, friend and exceptional American historian, disagrees.
In his article in Books and Culture
(January/February, 2006, pp. 9ff), contends that (1) Mormonism is a new religious tradition [many Mormons disagree, wanting their faith to be seen more in line with the Christian faith], (2) but it is not the first major religious tradition since Islam [nothing works to prove this point], and (3) McDermott sees significant challenges for Mormonism to grow as Stark predicts [too tied to America and American history; a low retention rate outside the USA; and its lack of a formal theology].