To promote peace, justice and freedom in a deeply divided world, the Catholic Church at Vatican Council II promulgated the declaration Nostra aetate in 1965,expressing its respect for the world religions and recommending dialogue and cooperation with their followers. This was a startling event, since from its very beginning the Catholic Church, and in fact all the Christian Churches, wanted to convert the entire world to the Christian faith. Nostae aetate also transformed the relationship of the Catholic Church’s to Jews and Judaism. This innovative teaching has raised theological questions that have not yet been fully answered. A certain lack of clarity has allowed some conservative Catholics to pretend the Church has not changed its mind. The present paper examines the new teaching in regard to Judaism and the world religions and record the gradual turn to greater openness on the part of Cardinal Ratzinger/Benedict XVI. That interreligious dialogue is capable of transforming the participants. Since religions also have a dark side, at times legitimating unjust regimes or fostering contempt of outsiders, it will be argued that that interreligious dialogue must also listen to the critical thinkers of the Enlightenment.