The fact is, Atheism is not opposed to religion, per se, but is at best (or at worst) indifferent to religion. Stalin was a Soviet first, an Atheist only incidentally.
Read about Vatican recognition of Christ-Killers, the persecution of anatomist Andreas Vesalius, J.G. Frazer’s exposure of Christianity’s sources, Isaac Asimov, Roman statesman M.T. Cicero, the not-so-secret Fabian Society, the cleric drowned for promoting baptism, and more!