When I saw this thread, I thought of Bishop Sheen who often commented on communism.
Then I saw this:
If by ‘communism’, you mean the systems that proceeded from the philosophies of Marx and Engels in the 19th century, then it seems quite clear: perceiving the history of humanity as purely the history of ‘class struggles’, Marxist philosophy sees religion as proceeding from society and the state (not from God or from humanity’s desire to reach out to God). Therefore, the function of religion is simply to provide a means by which the bourgeoisie might oppress the proletariat. (Remember? Religion is the ‘opiate of the masses’?) With this construction thus established, the only proper response to organized religion in a Marxist context is to destroy these structures by which humans are oppressed. These ‘atrocities’, viewed from the Marxist perspective, aren’t atrocities at all – they’re heroic, laudable actions intended to free mankind from tyranny!
I agree with most of this quote, but I’ll try to summarize what I remember Bishop Sheen said.
Karl Marx was a lifelong atheist. Early in his “career” ( he never actually had a job but lived off his mother’s money and later Engels, a model citizen

) he edited some atheist magazine. Many years later, he dreamed up a way to promote atheism. He thought of communism.
His “class struggle” theory, appropriated from Hegel and some sociologist of the day,. leaves out the individual as a personal agent determining his own fate. It’s the class, you know. Men are nothing more than soldiers in an army, ants in an ant colony, you get the idea. Only by acting in unison with the other soldiers in the army can the man prevail, in the class struggle. And so, individuality, self-determinism, self-responsitility, and everything else that makes a man a person is unimportant or don’t even exist. Man is an animal in a herd.
Of course, we know a man. may console himself in the midst of poverty and oppression by seeking God. This is the “opiate of the people”. So, to achieve success in the “class struggle” and get men fully committed to it , we must eliminate belief in God, and the communists try to do this.
Also, we communists claim “class struggle” is a law of nature. It’s natural. To make it sound scientific, to make it sound as inevitable as the fight of two ant colonies fighting each other for the same territory, we must exclude God and leave man nothing more than a clever animal.
Of course, there’s no such thing as a “class struggle”. There are the rich and the poor, the blacks and the whites, the intelligensia and the uneducated, but it’s not an "inevitable " law of nature that they will try to annihilate each other. Ways can be found to resolve their individual interests. In the U.S., we use democracy. Individuals in such a society can remain self-determining individuals.
Whether or not individuals believe in God is ( generally ) irrelevant ******** to the democratic process or other successful means of resolving class differences, so we don’t need either atheism or belief for this socio-political process.
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****** Yeah, I know how important religious beliefs are to a desirable society,

but here we’re talking in the broadest generalities.

Let’s not turn the topic into an argument about the value of Christianity. The topic is socio-political.