Yep. Hitler (a socialist, which is the prelude or the door that opens the way for communism) removed the Christian images and replaced them with images of himself and hung flags with rainbows,.....er.....I mean swastikas outside the buildings. (His numerous boyfriends were hidden until he killed them. He didn't need no stinkin rainbows.)
The Weimar Republic had also left German churches pretty jolly weak. The scene was set for a cakewalk by Satan. Until the still fairly heavily Christianized Allies were pulled into the picture.
And before Hitler there was the Terror in France, the Bolsheviks in Russia, the Communists, Socialists, and Anarcho-Syndicalists in Spain, the Christero War in Mexico, Mao, Ho, Castro, Pol Pot. It never ends. They all go for the religious first because they cannot abide being compared to an absolute moral standard.
Well quasily so (Russia figured in the defeat, and they were pretty much atheistic)