It is odd to see the level of denial of the atheist role in this. Marx, Lenin, Stalin, Mao, Xi, all hard core militant Marxist atheists.
No, I'll make another attempt to explain it to you:
Karl Marx went far beyond atheism. That God isn't real is a boring truism. What concerned him was why so many people nevertheless choose to believe in him. And he noticed that
their belief in God comforts them.
So the next question is: Why do they want and need to be comforted?
And he noticed that the reason is their ****** lives: If you lead a fulfilling life, you don't ask yourself, what's the point of it all?
But when your life seems pointless and meaningless, and you can't find a solution to your problems in reality as it is, you start looking for an 'answer'
beyond reality, it the realm of fantasy, in religion. You drown your sorrows, metaphorically, not in alcohol but in the 'opium of the people':
"Religion is the sigh of the oppressed creature, the heart of a heartless world, and the soul of soulless conditions."
The obvious solution to the problem of religion is to solve the
actual problems people have in
this world, the 'vale of tears' that makes them want and need religion. It is pointless to ask believers to give up their delusions as long as their
actual problems aren't solved:
"To call on them to give up their illusions about their condition is to call on them to give up a condition that requires illusions. "
Does that sound like the kind of guy who thinks that
persecution of believers is the solution? Marx thought that people like you already have a hard time, and he certainly didn't want to make it any harder. On the contrary.
Do you remember the quotation from
Capital about churches and monasteries being torn down and the monks joining the ranks of the proletariat? Did it seem to please him that this had happened? Or did he seem to pity the monks who found themselves in the very unenviable position of being forced to join the ranks of the proletariat, to find a way to make a living and having no way of doing so?
This is the difference between a Marxist and a hard-core atheist: We Marxists would rather discuss how to make the actual world a better place than nitpick inconsequential details and contradictions in terms in your Christian Bible. We find that endeavor very uninteresting.