This chapter examines how shifting frames of reference and definitions of orthodoxy influenced the emergence and success of Christian radicalism. It explores how clergy and popular radicals put various definitions of ‘infidelity’ and ‘enthusiasm’ to use in contemporary polemic, particularly in relation to education and the press. The threat to the social and political order could not be met in the same way as conservatives had attempted in the 1790s. The chapter shows how this was evident in the failed blasphemy trials of the late 1810s and early 1820s, the government’s hesitancy in prosecuting radical religionists and the increasing respectability of radical argument - both philosophic and popular. While common understandings of ‘conservative,’ ‘loyalist,’ ‘radical’ and ‘infidel’ in the 1790s meant that Christian radicalism garnered few supporters, the situation had changed markedly by the post-Napoleonic period. Christian radicals advanced a completely different notion of social control. They emphasized anew the life and teachings of Christ within Christianity.