Although Miller had never bothered to think about it, it was once out of these and other oceans of pine and beech that the old Germanic tribes had swarmed to be checked by Caesar at the Rhine. Later, converted to Christianity, they had paid lip service by day to the Prince of Peace, dreaming only in the dark hours of the ancient gods of strength and lust and power. It was this ancient atavism, the worship in the dark of the private gods of screaming endless trees, that Hitler had ignited with a magic touch.
—Frederick Forsyth, The Odessa File (chapter 17), 1972; with hyperlinks added
Is this literally true — that paganism/animism, residual from before the spread of Christianity, was partially responsible for the German populace's receptivity to Hitler — or is it a bit of invention? Or perhaps somewhere in between: it's not literally true as stated, but somehow metaphorically true?