Geffrey B. Kelly F. Burton Nelson, in their helpful book, The Cost of Moral Leadership: The Spirituality of Dietrich Bonhoeffer write how the spirituality of Bonhoeffer was founded on the Word of God…

His was an activist spirituality ever attuned to the Word of God both in his preaching and in is compassion for the downtrodden of German society. His was a spirituality that took seriously the cross of Jesus Christ standing astride that path he was called to enter upon (xv).