In 1937, on the threshold of Nazi Germany's war on the world, Dietrich Bonhoeffer wrote what turned out to be one of the most influential books of the century, "The Cost of Discipleship." In it, he challenged the faulty faith and compromises of German Christians, famously writing, "When Christ calls a man he bids him come and die." Now, eighty-two years after the book was first published, Charles Craig Lantz writes on Dietrich Bonhoeffer's doctrine...