 Following the German / Soviet invasion of Poland , the Pope 's first encyclical , Summi Pontificatus reiterated Catholic teaching against racial persecution and rejected antisemitism , quoting scripture singling out the " principle of equality " — with specific reference to Jews : " there is neither Gentile nor Jew , circumcision nor <unk> " and direct affirmation of the Jewish Revelation on Sinai . The forgetting of solidarity " imposed by our common origin and by the equality of rational nature in all men " was called " pernicious error " . Catholics everywhere were called upon to offer " compassion and help " to the victims of the war . The Pope declared determination to work to hasten the return of peace and trust in prayers for justice , love and mercy , to prevail against the scourge of war . The letter also decried the deaths of noncombatants . 
