Circular Reasoning in an Atheist Saying

A few years ago, I quoted the following atheist saying and pointed out that it requires ignoring the history of Communism:

With or without religion, good people can behave well and bad people can do evil; but for good people to do evil—that takes religion.

I was reminded of this by a a comment on Overcoming Bias.

On the other hand, it might make sense to classify Communism as a religion.

On the gripping hand, the most important reason to classify Communism as a religion is that it induced idealists to do evil … which makes the original statement look like circular reasoning.