Interrogating Barth's discipleship-shaped vision of sanctification, this book investigates both Lutheran and Calvinian source material to develop an account that differs markedly from other Lutheran and Calvinist perspectives. Highlighting the robustly theological and Christ-centred character of Barth's account, Chris Swann demonstrates that, far from merely valorising human activity, Barth advances an understanding of human moral agency, action, and suffering that is real but relative to the agency of God in Christ to which it corresponds analogously. With a focus on the role the image of discipleship plays in giving conceptual structure and shape to Barth's distinctive account of the correspondence between divine agency and sanctified human agency, this book evaluates the ramifications of his discipleship-shaped vision of sanctification. In doing this, it gives special attention to Barth's own personal mixed record with regard to Christian discipleship. Ultimately, Swann retrieves a number of important resources for contemporary theological ethics from Barth's theology of discipleship. In this constructive study, Chris Swann identifies the theme of discipleship as the governing motif in Karl Barth's theology of sanctification. Swann carefully contrasts Barth's program with the Reformers' and develops his argument in close and critical interaction with Barth scholarship past and present. Given the growing number of cursory accounts of discipleship, this study offers a much-needed corrective as Swann carefully probes the theological intricacies of discipleship and teases out their moral implications. Theologically astute and pastorally sensitive, Chris Swann recovers the importance of Christian discipleship for church and academy today. This study will be of considerable value both to the Barth scholar and any reader seeking a more nuanced account of discipleship that is firmly rooted in the doctrine of sanctification.