This chapter focuses on a particular dimension that is not generally connected with the name of the philosopher of Zarathustra: the heretical religious dimension both of Friedrich Nietzsche and Franz Rosenzweig. Friedrich Nietzsche's historic proclamation of the death of God has opened the gates of traditional metaphysical doctrines and popular world views to a new kind of criticism. With Nietzsche, a new kind of religiosity has opened, heretical religiosity. The concept of ‘God', said Nietzsche, continuing the tradition of the Young Hegelians, eliminates man's individual freedom and his existential being. The chapter examines the case-study of the Jewish philosopher Franz Rosenzweig, and his reception and critique of Nietzsche's enterprise. Rosenzweig is arguably the most celebrated Jewish thinker of the first half of the twentieth century. The Nietzschean revolution was that of abandoning the idea of teleological progress in favour of the idea of a process as teleological for itself.