De Pury joined the French Resistance and organized an escape route for Jewish refugees to leave France and enter Switzerland, hiding them in his home before helping them to the French-Swiss Boarder.
[1][6] With Denis de Rougemont, Henry Corbin, Albert-Marie Schmidt, and Roger Breuil, he co-founded the Christian existentialist magazine Hic et Nunc.
[9] On 14 July 1940 he preached against Nazism, Marshal Philippe Pétain, and the collaboration of Vichy France with Nazi Germany in a sermon titled You Will Not Steal.
In November 1941 he and his wife, Jacqueline, collaborated with Françoise Seligmann, a social worker who had recently joined Combat, to create a chain of escape to Switzerland, passing through Archamps.
[9] The Œuvre de secours aux enfants connected de Pury with Paulette Mercier, a French pharmacist and member of the resistance movement, who contacted Ruth Jaccard Monney and her parents, Arthur and Whilhelmine Jaccard, as well as the Dupeyreix family in Switzerland, to establish a network of resistance members across the border.
On 13 May 1943, while presiding over a church service, de Pury was arrested by the Gestapo and was detained for several months at Montluc prison, despite the petitions made by Cardinal-Archbishop Pierre-Marie Gerlier and Marc Boegner.
[1] He was transferred to Bregenz in Austria, where he was turned over to local authorities and released in an exchange for German spies who had been arrested in Switzerland at the end of October 1943.
[1] In 1976 Yad Vashem bestowed de Pury and his wife with the honor of Righteous Among the Nations for their work helping Jewish refugees during the Holocaust.