OK, some quick history fact check:
The ratio of protestants/catholics in the NSDAP quite reflected their ratio in overall society. There isn't any causal link between christian/catholic/protestant and being a Nazi. There were as well christian people resisting the Nazis. Some of them did it BECAUSE of their faith, others did it because they thought the Nazis to be bastards.
There was a heavy intermingling of both catholic and protestant church leaders with the Nazis, the Vatican gave them theri first international success and the Pope gratulated Hitler for invading Poland.
Some parts of the Nazi Party tried to fight against the churches not because they were against christianity as such, but because they were against its power and because it kind of was hard to compromise with their race ideology. They tried to "prove" that Jesus' father was a Roman officer from Germania, but that still left him half a Jew. Not good. Instead they focussed on old Germanic/Viking gods and symbols. That was especially popular within parts of the SS. It was even promoted to leave the church if you joined the SS, in spite of the buckles. Not because they were against god and christianity, but they didnb't like them to have a second master in this world. But the church gladly took them again after WWII
In fact, even today it's hard in Germany to take any interest in old pagean gods and symbols without automatically being sucked into a nationalist neonazi group or at least supporting them by buing the stuff. (unless you do it in university).
You can't really blame Ratzinger for having been a member of the Hitlerjugend. You had to be, more or less. Since he was an acolyte he was forced to be a member of the HJ anyway and even if you didn't have to join, it was suicidal not to join.