Luther’s Catechisms were, along with the Bondage of the Will, the only works of his which he considered worthy of preserving after he had died. To those familiar with his life and writings, that is remarkable. True, like all prolific writers, he wrote his fair share of junk; and unlike many such, he wrote his fair share of disgraceful venom as well. But to reduce his lasting contribution to a couple of catechisms and a polemic against a slippery man of letters seems a rather harsh judgment on his own work.

Yet there is a logic to this. Anyone who has read Luther’s Small Catechism will no doubt be struck by the simplicity both of its structure and its language. It is a masterpiece of Christian pedagogy. One reason for this, rarely noted, is that Luther was the first person to write a question and answer catechism who did so after first becoming a parent himself. If Christ demanded that his disciples should become as little children, Luther the theologian knew first-hand what that meant in terms of practicalities.

In fact, the Small Catechism represents Luther’s Reformation insight in both form and content. Not only does its teaching set forth justification by grace through faith, its form does so too, with its encouragement of childlike curiosity resolved by a childlike trust of God’s revelation in Christ. Rarely have form and content so perfectly matched each other in the history of Christian pedagogy.

The other significance of the catechisms is that Luther wrote them in the late 1520s when he was beginning to realize that Christ was not about to return and that the Reformation needed more ethical shape than he had anticipated. The official visitation of the parishes had revealed that, to use Luther’s own description, the people were living like pigs. The Reformer was faced with the fact that love, the dynamic motive for good works in his theology, had a specific ethical shape which needed to be explained in clear, simple, and precise terms to the people.

Any thoughtful pastor knows that the simple declaration of the great gospel indicatives of the life and death of Jesus Christ, God-for-us, will probably be sufficient for a small portion of his congregation to be able to connect the dots to a particular way of life. But for most Christians, more guidance is needed. In a world where the media preach a message of sexual license, selfishness, and material greed on a daily basis, people need a pastor to be a true under shepherd and to guide the sheep. They need constantly to be reminded that the Christian life of grateful love to God follows a particular ethical pattern. That is where the simple catechetical imperatives of Luther’s Small Catechism can be so helpful. Here the voice of a gentle father encourages and guides his children into appropriate behavior which reflects their status as those who are loved and protected by their true Father, God himself.

Finally, Luther’s Small Catechism points us to another vital element of church life: the simple preservation of the profound faith. I would suggest that, if it is in the Catechism, it is important; if it is not there, then it is not so vital. Sadly, I suspect that a glance at today’s evangelical conference circuit will reveal that the simple elements of catechetical Christian teaching are not enough to attract customers. We want something unusual or interesting: how Christianity connects to art or movies or (that most overworked term) culture. How often do we see yet another book, video or sermon series on sex because ‘the church doesn’t talk about it enough?’ I wonder how many consumers of such products could actually recite the Apostles’ Creed or the Ten Commandments, let alone articulate a basically orthodox Christology. The lesson of books like Luther’s Small Catechism is that, while sex might sell, simple truth nurtures, fortifies, and serves us well in life’s deepest and darkest moments.

Carl R. Trueman is Paul Woolley Professor of Church History at Westminster Theological Seminary and pastor of Cornerstone Presbyterian Church (OPC) in Ambler, Pennsylvania. His book Luther on the Christian Life will be available in February 2015.