On your observation about WW2 Germany, have you read Bonhoeffer: Pastor, Martyr, Prophet, Spy by Metaxas?
He covers in detail the rise of the "confessing" church and the rise of the Reich Church under Ludwig Muller.
I haven’t read this book, but am generally aware of how Hitler essentially took over the “mainline” denominations in Germany and turned them into the “Reich” church, except for the Confessing Church pastors. Martin Niemoeller was of course another resister to Hitler (although he turned out to be a lefty in the end). But Hitler had a harder time dealing with him initially, because he initially had been a Hitler supporter, and the Nazis had first pumped Niemoeller up as a popular war hero (U-boat captain in WWI before he became a pastor), so he had a lot of public support.
Geman churches in the 1930s not that much different than today, when the Mainlines have little to do with Jesus and Scripture and mostly to do with left-wing politics and social policies.