Marxism, labor, and the failed critique of religion

Marxism inherited from the Left Enlightenment the task of interpreting human history in materialist terms. Such an interpretation, to be credible, would need to be grounded in a materialist account of religion's origins and power. Marx and Engels, before calling for proletarian revolution and long before Volume I of Capital, specified that criticism of religion must precede all criticism. Yet neither they (nor later Marxists) developed a clear definition, nor spelled out the assumed relationship between disbelief and working-class liberation. Since - throughout the so-called Era of Secularism (roughly, from the Enlightenment to World War II) -working classes have tended to be more religious than middle classes, the "problem" of religion remained an obstacle to Marxian politics. Thus the failure of the Marxist critique not only left this problem unresolved, but, more importantly, left secularism itself intellectually disarmed against the resurgence of religious belief that followed the Second World War.