The evolution, spread, and practice of Islam is a world historical process that is characterized by multiple manifestations across historical time and individualizing manifestation at a particular point in history, and in particular places. This paper traces the divergent geographical spread of Islam to different regions of Nigeria. The paper asserts that the intersection of geography, ethnicity, and class configuration, and colonial history resulted in divergent trajectories for the evolution and practice of Islam and the emergence of an Islamic identity. It maintains that the conjuncture of several social processes resulted in the emergence of an Islamic identity that is relatively modern in orientation, which allows room for social reform while in Northern Nigeria, conservative Muslim reformers emerged as the dominant ruling elite. The paper maintains that the dominant ruling elites in the two regions used religion in different ways to promote national development --- a process that cannot by fully explained without looking at the intersection of geography, and other social-historical processes in the precolonial, colonial, and postcolonial periods. The paper concludes by drawing some theoretical generalizations about the relationship between religion and development.