Dietrich Bonhoeffer's pursuit of a sanctified life took a significant detour from the way in which he thought it would proceed. In seeking ‘good’ moral choices in the crucible of Nazi Germany, Bonhoeffer experienced a profound sense of what we now would recognise as moral injury, which proves to be a powerful and reflexive lens with which to examine his understanding of sanctification. Initially embracing pacifism as a fundamental pillar of Christian life, Bonhoeffer eventually became convinced that there are no pure or ‘right’ moral choices, only competing ‘wrong’ ones. He later wrote from prison that to be like Christ, and to come closer to holiness, was not to seek to avoid guilt, but to take on guilt for the sake of others. This recontextualisation of the idea of sanctification through the lens of Christ's substitutionary guilt suggests that for the responsible actor moral injury may be inevitable.