Editor's note: We are pleased to feature two excerpts from author Eric Metaxas' book, "Bonhoeffer: Pastor, Martyr, Prophet, Spy" in Fox News Opinion.

Book summary from publisher Thomas Nelson: From the New York Times bestselling author of "Amazing Grace," a groundbreaking biography of Dietrich Bonhoeffer, one of the greatest heroes of the twentieth century, the man who stood up to Hitler.

A definitive, deeply moving narrative, Bonhoeffer is a story of moral courage in the face of the monstrous evil that was Nazism.

After discovering the fire of true faith in a Harlem church, Bonhoeffer returned to Germany and became one of the first to speak out against Hitler. As a double-agent, he joined the plot to assassinate the Führer, and was hanged in Flossenberg concentration camp at age 39. Since his death, Bonhoeffer has grown to be one of the most fascinating, complex figures of the 20th century.

Bonhoeffer presents a profoundly orthodox Christian theologian whose faith led him to boldly confront the greatest evil of the 20th century, and uncovers never-before-revealed facts, including the story of his passionate romance.

To read Chapter 11: "Nazi Theology" click here.

To read Chapter 22: "The End of Germany" click here.