REad about Fritz Gerlich too, a Catholic German convert from Calvinism from the city of Stettin (in Pomerania, then Germany).
Gerlich was a critic of Therese Neumann, but was converted to the Faith by her. In 1934 he was killed by the nαzιs in the Night of the Long Knives and its aftermath in the nαzι prison camps. He opposed them out of Faith, and may be considered a martyr.
The (SSPX-ministered) Katholische Deutsche Jugend (Catholic German Youth) today revived Gerlich's magazine 'Der gerade Weg' (The narrow path or The just path), in which a lot of Catholic apologetics takes place.