This collection brings together a multinational team of fourteen scholars, mostly theologians, in a normative quest to decide how Western Christians should react to the dramatic decline of ‘established’ Western Christianity since the 1960s. By ‘established Christianity’ this collection means Churches with a longstanding cultural presence in Western societies, irrespective of legal status, and so it deliberately focuses on ‘mainline’ and/or ‘historic’ denominations, rather than immigrant Churches and/or Pentecostalism (p. 14). The contributors express a wide variety of opinions about the causes and consequences of ‘established’ Western Christianity's decline: since the collection's focus is expressly normative, its central division is between those who consider this decline to be worrying, and those who prefer to celebrate it. The former group is itself divided between those who believe the Churches should be more accommodating to local Western culture and those who believe the opposite, and so the volume does not offer an overall vision for the revivification of Western Christianity. Such a vision might be thought to require, amongst other things, a detailed understanding of the culture that it is seeking to reach, but unfortunately this volume's relative lack of historians means that it is relatively light on historical specificity. The strongest contributions produce detailed additional evidence to confirm the recent severe declines in ‘established’ Western Christianity, and accurately summarise current historical and sociological debates about causation without substantially adding to them; the weakest are simply impressionistic. There is little sustained attempt to provide a cultural analysis of secularity, nor to explain in detail what happened to Western culture in the 1960s, nor to account for the different growth patterns of ‘established’ and non-‘established’ Western denominations; nor, excepting in Esther E. Acolatse's Afro-Western analysis, is there much sustained comparison between Western and non-Western Christianities. Nor is there much discussion of Western moral tribalisation, the sacralisation of politics or secular shaming practices. Consequently, it is not obvious that many of these theologians do in fact possess a detailed understanding of the culture that they are trying to reach. Readers seeking a historical overview of the decline of Western Christianity since the 1960s would be better advised to consult Nancy Christie and others (eds), The sixties and beyond: deChristianization in North America and Western Europe, 1945–2000 (2013) or David Hempton and Hugh McLeod (eds), Secularization and religious innovation in the north Atlantic world (2017).