One of the greatest treasures of Jewish religious life is the siddur, the prayer-book. It reflects generations of spiritual struggle and exaltation, expressed in prayers of great poetic richness and nuanced theological reflection. While it is “one book,” it is made up of layers of texts, each one articulating its own way of expressing the deepest cares and yearnings of the Jewish heart. Yet for many Jews, this same book is an impediment to prayer. Forced to say someone else’s…