No one, no matter how brilliant, saintly or charismatic, ever has or ever will prove the existence - or non-existence -- of God. If the infinite God posited by Judaism since ancient times does, in fact, exist, then that God is by definition beyond human comprehension. And so this book does not attempt to prove the existence of God but rather takes an instinctual leap of faith, along with Moses, the Psalmists, Job, Maimonides and, yes, Albert Einstein, passing over the question of God's existence and asking instead the questions that have fueled the authentic religious enterprise for more than a hundred generations: What can we know of God and what does God require of us? A religion for adults seeks to probe the meaning and purpose of life. The very same may be said of science. Both reject pious platitudes and seek truth. Albert Einstein phrased it very nicely: "Science without religion is lame; religion without science is blind." What the author seeks to do, honoring both religion and science, is to introduce the reader to a God for Grown-ups.