The socialist analysis of religion derives from our basic materialism (not in the acquisitive sense, but how we view the production of wealth in society and the sort of ideas it gives rise to). Historical materialism traces how religions have evolved, from their beginnings in ancestor worship and private property in primitive societies, to established social institutions. For the materialist, in other words, society is not really under human control and humans really are at the mercy of blind, impersonal forces – in ancient times the forces of nature, in the modern world the economic forces of capitalism. Under capitalism people feel, rightly, that they are governed by forces they can't control but attribute this, wrongly, to forces operating from outside the world of experience. Churches of all types are then at hand for the sustaining of fear and superstition. For the socialist alternative to our lives being controlled by impersonal forces, we must bring about a society in which humans consciously control the forces of production. It is on this basis that we can say, rather than being abolished, religion can be expected to (as Engels put it in another context) "wither away". And it can be seen that the socialist case against religion differs from the usual humanist position: there are rationalist superstitions as well as religious. For humanists, criticism of religion is a process towards the eventual "triumph of reason". But they ignore the material circumstances which give rise to superstition.
Some folk claim that it cannot be said that it is a scientific fact that “God does not exist”, on the grounds that it cannot be proved that a non-interventionist god does not exist. Maybe but this depends on what is meant by “exist”. A non-interventionist god, precisely because it did not intervene in the world of observable phenomena, could not be detected and so to all intents and purposes does not exist in any meaningful sense of the word. As to an interventionist god, science does not need that hypothesis to explain the world of phenomena. Socialists try to operate in the same way that scientists do, by looking dispassionately at the evidence without prejudging the conclusions, by testing theories with prediction, and by challenging assumptions, including their own. It’s not always easy to do, but it’s not that hard either. Socialists are not on an anti-religious crusade but campaign to see the world through our eyes rather than someone else's. Religion is a class issue. We must understand our world as it is, make our own generalisations about it, come to our own conclusions. Religions are not deserving of respect just because they are religions; they must be subject to the same scrutiny as any other belief and cannot hide behind the notion that they are personal beliefs.
Atheists see themselves as defenders of the Enlightenment tradition of respect for reason and evidence against its traditional foe, religion. But they see nothing wrong about capitalism. Socialists share in the Enlightenment inheritance but recognise that the main source of irrationality in the modern world is to be found in the capitalist system of society. For socialists, therefore, the struggle against religion cannot be separated from the struggle for socialism. We fight religious superstition wherever it is an obstacle to socialism, but we are opposed to religion only insofar as it is an obstacle to socialism. Capitalism has many opiates to offer the unwary. Reject the pedlars, reject the product, but above all, reject a society which can create such an unhealthy psychological dependency. We need people that realise that the way society is structured is the result of people’s actions as they come together to produce the material things they need to exist, nothing more and nothing less. Belief in some super-natural force that steers it all would be counterproductive, to say the least. We need people who can critically understand the world and not get led along by conmen with their own agendas.