 In his 1939 Summi Pontificatus first papal encyclical , Pius reiterated Catholic teaching against racial persecution and antisemitism and affirmed the ethical principles of the " Revelation on Sinai " . At Christmas 1942 , once evidence of mass executions of Jews had emerged , Pius XII voiced concern at the murder of " hundreds of thousands " of " faultless " people because of their " nationality or race " and intervened to attempt to block Nazi deportations of Jews in various countries . Upon his death in 1958 , Pius was praised emphatically by the Israeli Foreign Minister , and other world leaders . But his insistence on Vatican neutrality and avoidance of naming the Nazis as the evildoers of the conflict became the foundation for contemporary and later criticisms from some quarters . His strongest public condemnation of genocide was considered inadequate by the Allied Powers , while the Nazis viewed him as an Allied sympathizer who had dishonoured his policy of Vatican neutrality . Hitler biographer John Toland , while scathing of Pius 's cautious public comments in relation to the mistreatment of Jews , concluded that the Allies ' own record of action against the Holocaust was " shameful " , while " The Church , under the Pope 's guidance , had already saved the lives of more Jews than all other churches , religious institutions and rescue organizations combined ... " . 
