This is an excellent book about the changes transforming religion in America. I recommend it wholeheartedly. I hope it will upend Europeans’ unexamined assumption that the US is an incorrigibly religious country with a rising fundamentalist core. Though a biblical 673 pages, the text yields easily to the educated reader, and cements the sterling reputation of Robert Putnam, whom The Sunday Times has called ‘the most influential academic in the world today’. Keeping pace with past achievements is no small feat for Putnam, aged seventy, with his bulging portfolio of intellectual smash hits, from earlier work on the decline of social capital and trust to recent explorations of the challenges that ethnic diversity poses to these social goods. Putnam has had the ear of world leaders of both left and right, notably Tony Blair and Presidents Clinton and George W Bush. It is one thing to excite policymakers, but Putnam has also managed to fire up a wide audience of general readers. This is a rare achievement given the reluctance of most lay readers to venture beyond either self-help or the sensory realms of history and literature. ‘I plough through data. That’s what I do,’ I once heard Putnam remark at a seminar. Unlike the pop sociology of a Malcolm Gladwell, Putnam’s work never sacrifices rigour for marketability, and this is its great strength.