What I mean is do we know that he truly believed in this ideology of antisemitism? There are examples of religious leaders just taking advantage of a situation and not really believing their message. Is there anything to suggest he did the same?
I'm not entirely sure what you're asking here. But if you're asking whether or not Hitler literally believed what he said about Jews, then the answer is yes, he did. The actions undertaken by the German state in World War two to remove the Jewish people from existence prove this.