Odd reply, although... I have always seen the monotheistic God idea as a leveler, very revolutionary in fact, king and peasant sharing the same God. That didn't exist throughout most of history. Christianity has a strong thread of lefty tradition regarding accumulation of capital, Jesus himself preaching equality and wealth would likely hinder entry to heaven. Marx did frame religion as a tool of the bourgeoisie, which is true, but so is the opposite - from Welsh preachers backing mining unions, jews in a kibbutz, to that Spanish priest who founded the world’s largest co-op - there are plenty of proto-communist threads within monotheistic faith.