What is the future of Christianity in the twenty-first century West? Are Western societies growing more secular, leaving cherished religious traditions behind? Or have modernity's secularizing currents generated equally powerful desecularizing and resacralizing currents? Should secularization theory, the dominant paradigm in the social scientific study of religion for much of the twentieth century, be thrown in the dustbin, as some scholars have suggested? Or does it remain useful, even indispensable, despite its limitations? How are globalizing processes, bringing diverse religious communities into increasingly close contact, affecting Western Christian communities? Such questions have attracted increasing attention from scholars in many disciplines during recent years and are at the heart of the essays in this volume.