This chapter tries to understand and analyze the organized form of religion in the British Muslim diaspora. It offers a detailed analysis of two mosques in London to elaborate on how the mosque becomes a focal point of the community. Through religious observances and the agency of assemblages, i.e., religious institutions and buildings propagate the idea of collectivity and Muslim ummah. In addition to this, this chapter explores how the mosque disseminates ideology as well as reflects community politics. The chapter also offers a discussion of alternative spaces, or what has come to be called third spaces, which bridge the gap between traditional religious institutions and young people’s requirements. This is studied with specific reference to one such alternative space called the Inclusive Mosque Initiative.