Bloss - just to be clear - I certainly didn't mean to say communism is a religion. Only that communism is not a good example to use as life without religion, because it isn't an 'ordinary' secular society, which enables tolerance. Just as some Islamic counties (Saudi Arabia, I think) would not be good examples of an 'ordinary' socitey based on religion, because religious societies usually act in tolerance too.
And I certainly didn't say that religion causes wars. people cause wars, and religion is just one of the things that people, in their falliability, include in the things they fight over. But not usually, I think, unless other associated factors like land or power or ethnicity, are bound up in the mix.