Actually, a far more fundamental (and thus far more interesting) question is: How did the highly unsavory (to put it mildly) characters – Adolf Hitler, his Nazis, Heinrich Himmler and his SS, etc. ended up being the servants of God? The Christian God?
The answer is simple and straightforward – since the birth of a human race, God had no other option other than to write straight with the crooked lines. Often very crooked. Actually, the medieval government and church officials (not to mention the knights) were in many aspects no better than “all of the above” – the Crusades are an excellent example (and so is the Holy Inquisition).
The situation in the 1920s was cut and dry, plain and simple, loud and clear – while both Nazism and Bolshevism were criminal and murderous ideologies (no doubt about that), the latter was the existential threat to the human civilization while the former was not.
The Bolsheviks were committed to physical annihilation of all religions Christianity, Islam, Judaism, paganism – all of them. Despite all their often radical anti-Christian rhetoric, the Nazis were far more realistic and pragmatic and so intended to establish some kind of mutually acceptable modus vivendi.
The Nazi program was Christianity-friendly and the first treaty signed by Adolf Hitler in his position as Reich Chancellor was the Reichskonkordat with the Holy Roman Catholic Church (the concordat with the Lutheran churched followed shortly thereafter).
The outcome of existential war ultimately boils down to which side is more spiritually powerful; consequently, only the more spiritually powerful ideology could have stopped Bolshevism in 1941.
The liberal ideology was far too weak hence God had not only to use Nazism the “alternative totalitarian ideology” but to actually create it using The Black Sun Society as His tool. God is Almighty, sure, but He still has no other hands but ours.
And in the 1920s He had no other hands but the Nazi ones. True, they were evil hands (in a broad sense); however, it was a far lesser evil than the Bolshevist one. The former did not present an existential threat to a human civilization and thus was acceptable to God while the latter was such a threat – and therefore was definitely NOT acceptable.
The Black Sun Society was a natural handler for Adolf Hitler and Heinrich Himmler (more for the latter than for the former, of course) and for the Nazis and the SS (ditto). For a very simple reason – they had practically identical objectives (including saving the Western civilization from being destroyed by the Bolshevist hordes).
Both wanted to make Germany, the Western Civilization and the White Race the masters/rulers of our world; both wanted sufficient Lebensraum and other resources for the highest possible living standards for its population; both wanted to transform Germans and the “Aryan Race” into genuine Übermenschen; both wanted to win the “existential racial war” with “Judeo-Bolshevism” (ideally by physically eliminating the first part altogether); etc.
The Black Sun Society and Heinrich Himmler (and his SS) were even closer because wanted to replace Christianity as the official religion with the neo-pagan one (based on the original German paganism); both wanted to make the Wewelsburg Castle Mittelpunkt Der Welt – spiritual center of the world; and both viewed the future pan-European state (dominated and essentially run by Germany, of course) as the Ordensstaat – the state based on (and run by) the neo-Teutonic Order based on pagan rather than Christian religion.
Not exactly the objectives of Christian God (to put it mildly) – which means that He had the same problem with The Black Sun Society that the latter had with its agents (Adolf Hitler, the Nazis, Heinrich Himmler and the SS) – they were His highly imperfect tools.
Unfortunately, there were no other tools at his disposal (even for the Almighty God, creating even acceptable tools was a very difficult endeavor) so He had to get by with what He had.
The Black Sun Society had no illusion about the future of Adolf Hitler, the Nazi regime (and the whole civilization of the Third Reich), of the SS and personally of Heinrich Himmler without the assistance of magical, supernatural energies (and thus objects, tools and technologies).
True, all the above constituted a formidable power and Adolf Hitler was an extremely powerful conduit of supernatural energies (possibly the most spiritually powerful politician and statesman in human history).
But their “aggregate opposition” was so powerful that the chances of winning the inevitable war without access to additional spiritual energies were practically zero. Consequently (and unbeknown to them, of course), the only way for them to win this war was to get connected to a sufficiently powerful source of divine energies.
The “Wewelsburg channel”. So almost as soon as the Nazis obtained the dictatorial powers in Germany, The Black Sun Society began (using Karl Maria Wiligut as their primary tool/medium) to work on exactly that – spiritually connecting the Wewelsburg Castle to Himmler and his SS (and via them – to the whole Nazi System).
Unfortunately, Heinrich Himmler did not cooperate – or at least did not cooperate well enough.