>>No one here has said that "Hitler's or Mussolini's motivations were Christian in nature." I have no idea who you are arguing with.<<
So you deny that Hitler was preaching Christianity in order to influence Christians? Aren't you saying that's what he was doing? In order for your premise to be true, Germans would have had to buy into the message. Since you're beating the historical fact drum, you can certainly produce some kind of evidence that his Christian message worked. You would also have to produce some kind of support from the Church, if we are to believe Christiany in any way supported Hitler's message. Otherwise it's just a madman spouting nonsense. (Hitler, not you)
Waiting ...
Seriously?
Let's see, we have Austrofascism, Rexism (the long form of the name is
Christus Rex, a Belgian Fascist movement that was very popular amongst the Walloons),
Monsignor Jozef Tiso was the Catholic priest and Fascist dictator of Slovakia during World War II. He allied the nation directly with Hitler and even helped invade Poland in 1939. I shouldn't even have to mention the Falange in Spain, who literally wrote Franco's policies after the Civil War. Clerical Fascism is a well known and documented historical reality.
That does not mean that there weren't great sacrifices made by Christians to do the right thing.
Here is but one example of a man who stood against both nationalism and Fascism and paid the ultimate price to do what was right. He put God before nation.
Hitler was a shrewd politician. The better question is, why would he bother making these appeals to Christians if there were no reason to do so? There is clear evidence that it worked. The truth is that Hitler did not kill 7 million people. Hitler, personally, probably killed very few - if any at all. He had a lot of loyal followers who were ready to pass orders down the chain of command and kill or be killed. That kind of loyalty does not come cheap. In a nation of Christian people, how did he attain this trust to carry out the war and the Holocaust? His and other Fascists work with and on Christian Nationalism helped them to achieve that.