Why are so many Americans leaving church? Half no longer belong to a congregation. A quarter now say they are unchurched, up from one in six a decade ago and one in twelve a generation ago, led by more than a third of young adults. Where have they gone, and what are they doing instead? What moves them? What should we make of it? What can we learn as well from those who have stayed or returned, and from congregations that have sparked their continuing...