Nazism was a political ideology, not a religion in the sense that it purported to point the way to God. Bolshevik Marxism was the same.
In World War II, we had the atheist Soviet Union alllied with Protestant USA and Anglican Britain, lined up against Lutheran Germany, Catholic Italy and Shinto Japan. Other major players were Confucian China and Hindu India, with Buddhist SE Asia and Moslem North Africa and Indonesia being areas where major battles were fought. Meanwhile the Judaic Jews were murdered by the million in concentration camps, with the atheistic Soviets killing millions in Gulags both before and after the war.
Which particular religion caused all that?