An interesting review of what sounds like a fascinating book – Eric Metaxas’s new Bonhoeffer: Pastor, Martyr, Prophet, Spy. WSJ writes:

As the storms of hatred raged in Germany, Bonhoeffer moved beyond “confession”—that is, preaching and writing—and into rebellion. By the summer of 1940, he was recruited by Adm. Wilhelm Canaris and others as a double agent for their conspiracy against Hitler, an effort that operated out of the Abwehr (Nazi military intelligence). Henceforth he would pretend allegiance to the regime and pass along to the conspirators—whose goal was Hitler’s assassination—whatever intelligence he could gather. He depended on deception for his survival.
It was a bizarre role for a religious man, and a hitherto loyal German citizen, to play. As Mr. Metaxas notes: “For a pastor to be involved in a plot whose linchpin was the assassination of the head of state during a time of war, when brothers and sons and fathers were giving their lives for their country, was unthinkable.” And yet it became thinkable for Bonhoeffer precisely because his understanding of faith required more than adhering to tidy legalisms about truth-telling and nonviolence.
Mr. Metaxas notes that Bonhoeffer drew deeply from historic Christianity, especially its emphasis on the love of God expressed in the life and teachings of Jesus. Bonhoeffer also had an extraordinary capacity for empathy, responding with ever more horror to the plight of those around him. In his book “Ethics” (1949), he chastised those who imagined they could confine their faith to the sanctuary and still live responsibly in an unjust world. In “The Cost of Discipleship” (1937), he made unreserved obedience to Jesus—in every realm of life—the mark of authentic belief. “If we worry about the dangers that beset us, if we gaze at the road instead of at him who goes before, we are already straying from the path.”

Bonhoeffer’s is a story that the most imaginative novelist could not have invented. But that’s familiar ground to Metaxas, who also wrote Amazing Grace: William Wilberforce and the Heroic Campaign to End Slavery.