The Nazis were not atheists. They were quite mystical on the upper levels, and generally conventionally religious on the lower levels. Every German soldier wore a belt buckle on which was emblazoned "God (is) With Us", in German words.

They committed some of the greatest crimes in history.

The Holy Roman Empire/Church of Rome committed some of the greatest crimes in history, wiping out vast numbers of people merely for having a different belief in some way.

There are numerous other examples...

On the other hand, atheists also have committed great crimes. Stalin murdered millions, so did Mao, and so did Pol Pot.

The fact is, crimes are just as easily committed by atheists as by fanatical religions.

And the REAL truth is, atheism IS a religion, but it's not a religion that theorizes or includes the existence of "God", that's all. It has its own chosen idols to bow down to, among which are: materialism, survivalism, profit, the ego, a political theory, a political party, and/or a charismatic authoritarian leader.

Nothing is more dangerous than a fanatic...whether or not he is an atheist OR a member of some traditional religion like Christianity, Judaism, or Islam.

We need compassion, wisdom, and Love. Those can be found and developed either within organized religion or outside of it.