Book excerpt: How did the universe begin? Can God's existence be proven? Do humans matter more than animals? For many years people have sent the scientist-turned-priest John Polkinghorne these and other questions about science and belief. In question-and-answer format, Polkinghorne and his collaborator Nicholas Beale offer their highly informed opinions about some of the most frequently asked of these questions. Readers can follow their own paths through the book, selecting questions that interest them and looking at the additional material if they choose. This unique book will help Christians clarify their beliefs regarding difficult issues and better face challenges--from within and from others--to their faith.