This study investigates the role of religion in nation building processes of Turkey and Pakistan. Current literature on these two countries is divided between those who claim that Islam was an essential arm of nation-building and those who claim that the role of Islam, if there was any, was merely instrumental and strategic. In that it reflects the divide in the wider literature on nationalism; between those who consider nationalism as a modern and secular(izing) phenomenon and those who underline the importance of pre-modern identities in general and religion in particular in the nation formation.This thesis aims to go beyond this dichotomy by pointing that religion in any nation-building plays a much more complex role. It can be crucial for nation-building at a certain stage, but it may be useless, irrelevant or even an impediment at another stage of nation-building. This dissertation argues that since nation-building is a process of homogenization, the role of religion can be best analyzed through its contribution to this process at the national level. Assimilation and exclusion are two means of homogenization and religion often contributes to national homogenization by excluding members of different religious communities. This is particularly true for the multi-ethnic and multi-religious societies, with an imperial legacy. By understanding nation-building largely as a process of homogenization, this thesis builds on the legacy of Ernest Gellner and his works on nationalism. However, it aims to go beyond Gellner by bringing the role of religion to the process of homogenization. Another important aspect of this study is that homogenization is discussed in the context of the emergence of modern state and the transition from empire to nation-state.