The special section on the Protestant Reformation we’re planning for our Oct. 28 issue will include reviews of books about the world-shaking changes that began on Oct. 31, 1517. The best new book on Luther I’ve found is Luther on the Christian Life, by Westminster Theological Seminary professor Carl Trueman—so I interviewed Trueman in front of students at Patrick Henry College. Here are edited excerpts.

We’re close to the 500th anniversary of the beginning of the Protestant Reformation. Martin Luther famously contrasted a “theologian of glory” with a “theologian of the cross.” What’s the difference? Theologians of glory make God in their own image and assume God thinks and operates in a way closely analogous to the way we operate as human beings. Simple example: If I want you to like me, I will do nice things for you. We assume that God is that way: We do good works for God, and God will reward us for them.

And theologians of the cross? They humbly understand God to be the way He has revealed Himself to be in the broken flesh of Jesus Christ hanging upon the cross. That contradicts human expectations.

Today’s prosperity gospel: preached by theologians of glory? Luther would say: What do you mean when you say, “God blesses you”? Luther would say: Look at the cross. No man more blessed than the Lord Jesus Christ ever walked upon the earth, and the pathway of blessing took Him to death on the cross. Christian blessing is spiritual, not material. Prosperity gospelers understand blessings in crudely material terms: classic example of a theologian of glory’s thinking.

‘For Luther, the way to heaven is paradoxically through hell. The way to life is through death.’

Luther said sunny stories of our basic goodness are attractive in their cheeriness, but they are actually terrible, enslaving lies. In some churches these days, do we more often hear cheery stories about how good we are, than about who we really are? Many churches do parrot back to people a particular view of themselves that they want to hear: how great they are. But Luther saw that the first thing human beings need to understand about themselves is that they’re dead in their trespasses and their sins: Their rebellion has cut them off from God, and if you don’t understand that, you will never understand the importance and the need of the Savior.

Was Norman Vincent Peale (The Power of Positive Thinking) also a theologian of glory, within Luther’s understanding? Luther would say, “What is positive thinking? Positive thinking is ultimately deceptive!” Because, for Luther, the way to heaven is paradoxically through hell. The way to life is through death. That’s what baptism speaks of, for example, for Luther. Baptism is about dying and rising. You can only be resurrected if you first die. Well, how can one think positively about death? How can one think positively about hell? One cannot!

When Luther advised, “Sin boldly,” what did he mean? Luther saw that many who take Christian life seriously might tend to despair, because as Christians we become more acutely aware of how we rebel against the Lord on a regular basis. Luther says if you’ve sinned boldly, repent even more boldly. The blood of Christ is greater than any sin you may have committed. You’re not to worry and despair over your sins: Look toward the sufficiency of the Lord Jesus Christ in faith and repentance as the one who saves. We need constantly to combat the tendency within ourselves to think we are righteous before God because of our own intrinsic righteousness.

So it’s good to hear sermons about God’s mercy, but to appreciate them do we also occasionally need to hear sermons about God’s wrath? Once in the late 1520s and once in the late 1530s some Lutheran pastors started simply to preach grace, simply to preach the gospel. Luther opposed that because he thought it gave an imbalanced view of what Scripture teaches, and ultimately downgraded the value of grace. We can only understand the full extent of God’s love in taking on flesh and dying for us by understanding the problem being addressed. So that requires preaching of the law.

Since the good news stands in contrast to the bad news, how should we use natural law: Does Luther basically say that reason leads us astray, since reason would never lead us to the God revealed on the cross? Luther discussed both the vertical and the horizontal. Vertically, Luther has very, very limited use, if any use at all, for reason. Horizontally, in terms of the way the civil world is organized, Luther would probably say, “It stands to reason that you should be good to your neighbor, that the wicked should be punished, and the innocent protected. But that won’t get you to heaven.”

Luther sees reason as captive to our sinful desires, so we almost instinctively bend our thinking to justify our actions? Yes. Luther’s view of the intellectual impact of human sin would leave him very, very skeptical about the usefulness of arguments from natural law even in the civic realm. I think of Sherif Girgis, Robbie George, and Ryan Anderson’s book, What Is Marriage?, which is probably the single greatest and most unanswerable natural law case for traditional marriage, and which has probably persuaded nobody to change his opinion.

Do natural law arguments convince anyone? They convince people when it appears to be in their best interest: So I could see a case being made for being good to your neighbor because it’s in your best interest, because then your neighbor will be good to you. So one would see that sin will not completely destroy the logic of natural law, but it may dramatically alter the motivations for holding to it.

Maybe it’s more in my interest to lord it over my neighbors so they’ll do what I want them to do all the time. True.

What do you think is the biggest challenge facing evangelical churches today? How can the church, when it has one or maybe two hours on a Sunday, truly shape people’s minds and characters, when there is so much in the wider culture that is now directly antithetical to Christian ethics and Christian ways of thinking?

OK—how? It’s hard. Strong and faithful preaching of the Word of God. Preaching is not simply explaining the Bible. Luther was very strong on this. When the Word is proclaimed, the Holy Spirit takes that Word and works miracles in people’s hearts. A strong pulpit ministry is absolutely central to the church, along with vibrant worship services that in many ways embody the gospel: times of confession, forgiveness, and intercession, with a benediction at the end.

What happened to the relics? Wittenberg’s collection included a vial of breast milk from the Virgin Mary and a twig from the burning bush. What happened to those? I suspect they were quietly disposed of in the local sewer, but I have absolutely no idea.