The Holocaust anchors more modern Jewish thought than any single event since the destruction of the Second Temple, and the responses to it map the whole range of possibility. Richard Rubenstein argued in 1966 that after Auschwitz the traditional God of history could no longer be affirmed. Emil Fackenheim answered with what he called a 614th commandment, added to the traditional 613: Jews are forbidden to hand Hitler posthumous victories, forbidden to despair of God or of the world lest Judaism perish by their own hand. Eliezer Berkovits reached for the older category of hester panim, the hiding of the divine face, holding that faith after the Shoah must carry both the protest of Job and the endurance of the generations. Elie Wiesel made memory itself the religious act: to testify, so that the dead are not murdered twice.
Christian theology was confronted from the other side, with the churches' own inheritance. The centuries of the deicide charge, the ghetto and the anti Jewish sermon stood exposed as part of the soil in which the catastrophe grew, and the reckoning, documented for the Catholic case by Michael Phayer, moved from silence toward repudiation: the Second Vatican Council's Nostra Aetate in 1965 rejected the charge of collective Jewish guilt, and later statements from many churches went further.
Observance has absorbed the event. Yom HaShoah entered the Jewish calendar in 1951, kept in the spring between Passover and Independence Day, and the six million are named in liturgy, memorial and stone across the Jewish world.
Sources God's Presence in History: Jewish Affirmations and Philosophical ReflectionsEmil L. Fackenheim with The Catholic Church and the Holocaust, 1930-1965Michael Phayer, The Destruction of the European JewsRaul Hilberg