'God revealed in the flesh', the God-man Jesus Christ, is the holy mystery which theology is appointed to guard. What a mistake to think that it is the task of theology to unravel God's mystery, to bring it down to the flat, ordinary human wisdom of experience and reason! It is the task of theology solely to preserve God's wonder as wonder, to understand, to defend, to glorify God's mystery as mystery.
With these nearly mystical words, Dietrich Bonhoeffer, in a 'Circular Letter' of Christmas 1939 to the brethren of the Finkenwalde seminary and the pastors of the Confessing Church, describes the task of Christian theology in general and of Christology in particular: to praise the glory of God in the wonder of his incarnation.
It has become customary to regard Christology as the centre of Bonhoeffer's thought. And indeed, the question 'Who is Jesus Christ?' forms the cantus firmus of Bonhoeffer's theological development from the beginning to the end. This question, originally latent in Sanctorum Communio, becomes explicit in Bonhoeffer's academic Christology lectures of 1933, that crucial year of German history in the twentieth century when Hitler came to power. And still in 1944, in his Letters and Papers from Prison, the programmatic question Vho Christ really is, for us today' forms the starting point of Bonhoeffer's new theological reflections.