Darrell Guder has played a significant role in the re-examination of the Christian Church and its relationship with contemporary Western society. The book he edited in 1998, Missional Church: A Theological Vision for the Sending of the Church in North America, not only popularised the neologism ‘missional’ but also provoked debate about its call to readdress ecclesiological and hermeneutical issues so that the church remains faithful to its calling. Guder, a Reformed theologian influenced by Karl Barth and Lesslie Newbigin, brings to current missiological questions the depth and perception of a systematic theologian seeking innovative theological responses to post-Christendom situations. He has contributed to the Gospel and our Culture network, and this volume is published in a series of the same name, which intends to ‘foster the missional encounter of the gospel with North American culture’. Called to Witness is published at the end of Guder's career and comprises his further reflections on missional theology from his teaching at Princeton Theological Seminary from 2002 to 2015 as Professor of Missional and Ecumenical Theology.

The first three of the eleven chapters examine what is meant by missional theology and define its task as ‘to accompany and support the church in its witness by testing all that the church says and does in terms of its calling to be Christ's witness’ (p. 13). Five chapters address church as missional community, its understanding of scripture, theology and its lived witness. It includes a re-examination of the Nicene ‘marks of the church’ that Guder has discussed before, and which suggests that the Nicene Creed be read backwards, starting with attention to ways of being a church that is ‘one, holy, catholic and apostolic’ in contemporary society. Two chapters consider leadership and theological formation. The final chapter addresses the challenge of ecumenism, noting a stagnation of the twentieth-century ecumenical endeavour and calling for a unity that is part of the lived reality and public nature of the church, not an internal, doctrinal affair. There is little detailed discussion of contemporary Western culture. Guder writes from a concern that the Western church is shrinking, and he expects his readers to be aware of the difficulties. Rather than lament its decline, he rejects the ‘Christendom’ expectation of ecclesiastical influence in governance and society and calls for a reconsideration of theology in order to witness in a world of changed expectations. He places his concerns on a global canvas alert to church growth outside the West, but he deliberately addresses the perceived bewilderment of the North American church in particular, with references to similar patterns in Western Europe. Arguably, this cultural lens, which attempts to respond to particular regional issues, reduces the vision of catholicity.

For readers who are unfamiliar with missiological reflection in Western cultures Guder's book provides a good introduction to current themes from an eminent proponent of their importance. He writes thoughtfully and clearly, and his chapter-length engagement with particular subjects is helpful and accessible. The chapters have all been presented elsewhere as lectures, and there is some repetition. Readers may be disappointed that there is no bibliography or index by which they could develop their reading. More concerning is the apparent lack of engagement with some recent works of significance; The Witness of God by John Flett, for example, addresses the Trinity, missio Dei, Barth and church, but Guder does not mention it. Nor does he seem aware of comprehensions of secularism that consider it a phenomenon alongside religious belief and practice, rather than a something which takes over religious space. Readers familiar with current missional themes and thought may well find some nuggets of interest in Called to Witness but overall it is unlikely to develop their understanding further.