More specifically they worship the state. They replace god with that (compared to theocracies).

Communism is a mystical collectivist ideology, that proclaims the magic will of the people can make the impossible, possible. It pretends to bring reality under the rule of the subjective whim, such that if enough people believe something then it will be so. That's classic doctrine however, and it's questionable how much of that style of Communism still exists in China, they seem to be far more practical in their application.