“Luther had grasped by faith the free and unconditional forgiveness of all his sins. That experience taught him that this grace had cost him his very life, and must continue to cost him the same price day by day. So far from dispensing him from discipleship, this grace only made him a more earnest disciple. When he spoke of grace, Luther always implied as a corollary that it cost him his own life, the life which was now for the first time subjected to the absolute obedience of Christ. Only so could he speak of grace. Luther had said that grace alone can save; his followers took up his doctrine and repeated it word for word. But they left out its invariable corollary, the obligation of discipleship.
…The justification of the sinner in the world degenerated into the justification of sin and the world. Costly grace was turned into cheap grace without discipleship” (49-50).