you can't say you don't believe in God, but do believe in Communism.

Au contraire. For many people, it is purely a rejection of one thing, rather than an embrace of reason, rational thinking. It may very well be that it is impossible for our species to engage in rational thinking on any large scale. The best we can hope for is that people will blindly believe something that is slightly less evil than the alternatives.

Communism working

I agree, but then again, I don't believe that China is communist.