I don't know if Hitler was a creationist but he was decidedly anti-Christian. One of the policies of the Third Reich was to marginalize Christianity and supplant it with a state religion based on ancient Germanic paganism.
One could say the same of Americans, with their Easter bunnies and Christmas trees.
The fact is that Hitler put Christian symbols and slogans on all kind of Nazi paraphernalia. He hobnobbed and had photo ops with bishops and cardinals.
I am not asserting he was sincere; I am asking why his supporters who were Christian fell for it.
Do you really think he cared anything about ideas other then whether they could be paraded to further his aims?