R. Jonathan Sacks, A Letter in the Scroll (via Hirhurim):

Can we really know whether faith is justified? Do we, citizens of modernity and post-modernity, not take for granted what Hume, Kant and Nietzsche labored to establish, that the existence of God cannot be proved? And do we not as Jews–always inclined to rationality, and now chastened and chilled by the Holocaust–have more reason to doubt than most? Yet I have to admit, even as a professionally trained philosopher, that I am unmoved by this whole trend of thought, rendered trivial by its own circularity. Of course it is possible to live a life without God, just as it is possible to live a life without humor, or music, or love; and one can no more prove that God exists that one can prove these other things exist to those who lack a sense of humor, or to whom Schubert is mere noise, or love a figment of the romantic imagination…

Jewish faith is not a metaphysical wager, a leap into the improbable. It is the courage to see the world as it is, without the comfort of myth or the self-pity of despair, knowing that the evil, cruelty and injustice it contains are neither inevitable nor meaningless but instead a call to human responsibility–a call emanating from the heart of existence itself