Of course Communism was a religion...just not a God-based religion, that's all. It was (and is) a political religion. The same can be said of Naziism, Fascism, and that nebulous set of grand expectations called "the American Way". ;-) They are all political religions, complete with a set of sacred historical figures for inspiration, some sacred documents, and some sacred symbols for the worshipful masses to focus upon and defend with their lives.

Whether or not "God" enters into the picture can vary. You can base a political religion on "God"...or on atheism...or on the profit motive...or on sheer pragmatism...or on anything else that provides a powerful motivator.

The notion that there is...or is not...a god cannot be proven or disproven, it is a matter of subjective opinion. The same is true of the notion of romantic love. Does it exist? Or is it a fantasy? The answer is a purely subjective matter and cannot be proven or disproven in any empirical fashion.

Why? Because the idea of god and the idea of romantic love both concern inner perceptions...not outwardly objective phenomena that can be measured. One man's inner perception may be another man's sheer fantasy, but that doesn't mean the inner perception isn't real....it's just not a physically observable phenomenon, that's all.