"Grace of God," "divine grace," God forbid," "God be thanked," and "God knows," are not phrases likely to be used by an atheist certainly not on a regular basis. Yet, Mein Kampf, the book by Hitler that most scholars view as the blue print for Nazi Germany is littered with these phrases. The false notion that Hitler was not only an atheist but epitomizes what it means to be an atheist has been used by Christian critics for decades. I am not sure whether it stems from ignorance, willful or otherwise, or from something worse. This myth is not promoted solely by right wing religious critics of atheism. There are numerous liberals and moderates who have promoted the lie as well. Why? Anyone with a functional brain and an interest in the truth could easily figure out that it is a blatant falsehood. Is it a defensive projection? It can easily be debated whether Hitler was a "good" Christian or not but it is no way debatable that he was Christian. Get transcripts of his speeches or read Mein Kampf. They may not be easy to stomach but they are pretty clear on Hitler's personal views.
"Therefore, I believe today that I am acting in the sense of the Almighty Creator: By warding off Jews I am fighting for the Lord's work." (V.1 Ch.2, p.84)
"This perseverance is only and always the result of a certain spiritual conviction alone. All force which does not spring from a from spiritual foundation will be hesitating and uncertain." (V.1 Ch.5, p.222)
"The result of any crossing, in brief, is always the following:
a. Lowering of the standard of the higher race,
b. Physical and mental regression, and, with it, the beginning of a slowly but steadily progressive lingering illness.
To Bring about such a development means nothing less than sinning against the will of the Eternal Creator" (V.1 Ch.11, p.392)
"Should not the same renunciation be possible if it is replaced by the admonition finally to put an end to the permanently continuous original sin of race poisoning and to give the Almighty Creator being as He Himself created them?" (V.2 Ch.2, p.611)
All excerpts from the annotated edition of Mein Kampf
So if you hear anyone state that Hitler was an atheist make a point of correcting them.