Metzger had served as military chaplain, in the German Imperial Army during World War I. Metzger became convinced that “future wars have lost their meaning, since they no longer give anybody the prospect of winning more than he loses.” At war's end, Metzger established the German Catholics’ Peace Association.
[1] Metzger was targeted by the Nazi authorities and arrested on several occasions by the Gestapo.
He was arrested for the last time in June 1943 after being denounced by a mail courier for attempting to send a memorandum on the reorganisation of the German state and its integration into a future system of world peace to Erling Eidem, the Swedish Archbishop of Uppsala.
[2] Social worker Gertrud Luckner was another high-profile member of the Association.
For her work aiding Nazi victims including the Jews and foreign prisoners of war, Luckner was arrested in 1943 and only narrowly escaped death in the concentration camps.