Marxism is based on a purportedly scientific narrative that describes the relationship of capital with labor, that says nothing about agrarian economies. Since all his city dwelling corevolutionaries were killed, Mao had to change the doctrine. In so doing, he negated the whole of actual Marxism. This demonstrates that he was not fulfiling a historical necessity, so much as using History as a rhetorical rationalization to implement his OWN policies.
Skillful propaganda, of the sort both Lenin and Mao used–when you get people hooked–is like a drug, where people want to be told what to do. Once this is in place, if your story–say class warfare–doesn’t work out, you change the story, so that people can be led in circles for lifetimes. For the people following, you can consistently generate feelings of usefulness and goodness, since they are doing what they are told, and part of the story they are told is that your doctrine partakes in some essential way in “goodness”.
Leftism really does have many of the structural attributes of a cult, in which people are turned into simulacra of human beings. Whatever you say, they do, without question.
Marxist have this idea of History. They say “History dictates that we do x, y, and z”. This occupied the place in a propagandized populace of God. What History says, is like what God says. You can neither deny it, nor oppose it. It is, you are told, a factual reality, denying which makes you a lunatic.
Once you do this you can rationalize anything. History dictated our own Manifest Destiny. The real, actual process is simple: decide what you want to do, then base it on some non-material, unaccountable force.