This essay argues that essentialist models of modernity are always ideological, and that Britain's dominant ideology of modernity was transformed from the mid-1950s, with revolutionary consequences for British Christianity and secularisation. Before the mid-1950s 'Christian civilisation' was commonly considered more advanced than secularity, which was associated with Stalin's Soviet Union. The mid-1950s global crisis, however, created widespread belief in an unprecedented new 'modern world'. This perception rapidly legitimated the further belief, promoted by radical Christians, that 'the modern world' is inherently 'secular'. Once accepted by the national media, these ideological beliefs about modernity made possible the 1960s 'secular revolution'.