It is not a coincidence, in my view, that strongly spiritual visions of the Christian life gained great traction after the War that did not promote deep engagement with the world (e.g., "higher life" spirituality, premillennial dispensationalism focused on interpretation of biblical prophecy about the End Times, and eventually Pentecostalism). These developments may have taken place even without the War, but their appeal was probably strengthened because they mostly set aside deep concern about the Here and Now.

On the more liberal side, there was a turn toward ethical reasoning based more securely on sensibility about what was right—that is, if we know that slavery is wrong and yet Scripture seems to sanction slavery, we probably need to revise our views of biblical authority to give more stress to those moral intuitions. A fine new book by Molly Oshatz, Slavery and Sin: The Fight Against Slavery and the Rise of Liberal Protestantism, explains the latter connection very well.

You point out that in 1860, a third of Americans were member of churches, but twice that number were active in church life. Today, 2/3 of Americans claim church membership, but only half of them attend regularly. How do today's circumstances determine the Bible's place in national debate and discourse?

In the Civil War era, arguments taken directly from Scripture factored large in the nation's public life—as the prime example, if the Bible was thought to allow for slavery, or if it was thought that it did not, was a very important conclusion for almost everyone in public life. Today, while there is a remnant of that sort of direct influence, there also exist many more sources of personal and public authority, many more publicly influential voices that do not reference the Scriptures, and even more disputing than in the Civil War era as to what a proper application of Scripture to public life would look like.

So far this election year, Americans seem to be thinking less about military war and more about culture war. What would you want today's culture warriors to learn from the history of theological disputes around the Civil War?

Study of the Civil War should be a humbling experience. The death and destruction, which no one anticipated when the conflict began, was due in part to the righteous self-confidence with which the two sides entered the war.

It is also important for people in our generation to realize how complicated historical change is. The most important moral victory of the war, the abolition of slavery, was not a prime consideration at the start of the conflict. And when slavery was abolished, it did not lead to equal rights for African Americans. When God's sanction is applied directly to public events, it is more difficult to engage in public dialogue and political negotiation.

The ideal, in my view as a Christian believer, is to approach public life as Abraham Lincoln came to do: believing firmly in God's rule of the world, but always willing to hear others out to help me understand exactly what that rule means for specific political actions.