You are wrong about that. Even before the National Socialists cared about attracting an electoral majority, their ideology was infused with Christian themes.
"In Christ, the embodiment of all manliness, we find all that we need. And if we occasionally speak of Baldur, our words always contain some joy, some satisfaction, that our pagan ancestors were already so Christian as to have indications of Christ in this ideal figure"
"Christ stands never otherwise than erect, never otherwise than upright...eyes flashing in the midst of the creeping Jewish rabble...and the words fall like lashes of the whip:"Your father is the devil ()
Deitrich Eckart, "Bolshevism from Moses to Lenin: a conversation between Adolf Hitler and myself" (1924)
The National Socialist movement was often described both among themselves and to the public, as a struggle between opposites: Christianity-Judaism, creation-destruction,good-evil, God-Satan, redemption-annihilation.
Has Steigmann-Gall pulled the wool over your eyes with his false and misleading book?
More later, I have to go.
You might think though about the many Darwinian themes in Mein Kampf. Also, Hitler's concept of Christianity was identical to Nietzsche's.