Karl Marx believed that he inherently knew the true nature of "The True Human". He believed that True Humans were inherently collective in nature meaning that individual human people didn't live and work for themselves but individual humans lived and worked for the benefit of all humans as a collective. He believed that only a True Human would understand this nature of humanity and such an individual with this special knowledge would be able to awaken this knowledge to other True Humans through his outlook of how humanity works - the material dialectic. He called these True Humans as "the Communist Man". The status of Communist Man is Marx's vision of the ultimate humanity in which humanity cannot progress further and no more history needs to be recorded; the ultimate point of humanity will never change after this because the ultimate True Human will always produce the exact same ultimate result of the ultimate True Human.
How the state (human official government) works in his material dialectic is that it works to govern individuals to produce more Communist individuals, each Communist individual are all working towards the ultimate goal of the True Human/Communist Human. Marx's vision is that there will be a future point in history in which the state understands itself to be superfluous in governing (producing) individual humans that produce more Communist individuals. This is Marx's freedom in which all individuals that make up all of humanity have no more personal desire to hoard private property. This is the meaning of Marx's freedom as he equates freedom with Communism - the status of the True Human who has no need to hoard any private property.
These are a few suppositions of Marx and these suppositions have no basis in any kind of historical or biological evidence; these suppositions are a kind of gnostic special knowledge that are supposed to exist in reality outside of reason and observation. That is, Communism is a crackpot religion that's just as kooky as any of the other gnostic belief systems that perpetually plague human society.