If asked to list important lay Christian writers from the twentieth century, people tend to list names such as GK Chesterton, CS Lewis and JRR Tolkien. One name that will probably not figure is John Buchan. Yet this omission is unfortunate, because Buchan was one of the twentieth century's most prolific and widely read British Christian authors, and, more importantly, he is an author whose works still have much to teach Christians today.

Buchan is best remembered today as the author of The Thirty-Nine Steps, but there was far more to his life than the writing of this single book. Born in Scotland in 1875 in relatively humble circumstances as the son of a minister in the Free Church of Scotland, Buchan was a journalist, historian, biographer, novelist, poet, historian, lawyer, and politician who died in office as the Governor General of Canada in 1940.

As his most recent biographer, his granddaughter Ursula Buchan, explains in her book Beyond the Thirty-Nine Steps – A Biography of John Buchan, Buchan was a devout Christian whose 'Christian faith was the foundation of his understanding of the cosmos and the motivation for his way of living.'

Because his Christian faith shaped the way Buchan saw the world, it is also reflected in his writings and, the result is, as I have noted, that his works have important lessons to teach Christians today.

Today the proponents of 'critical theory' argue that right and wrong are invented by groups with political power in order to support their dominance over others. Buchan, however, stands in the Christian tradition of moral realism. In his writings he teaches us that right and wrong, good and evil, are not mere human political inventions, but have objective existence, and that human beings have to take the right side in the battle between them.

Today it is widely believed that the course of history is either a complete accident, or wholly determined by human activity. Buchan teaches us, on the other hand, that what happens in history is the result of the providential action of God. However, this does not mean that human beings have no role to play. Their role is to trust God and work with his providential activity by performing the tasks he gives them to do.

As the American Walter Blenkiron puts it in Buchan's novel Greenmantle, 'I believe in an all-wise and beneficent Providence, but you have got to trust him and give him a chance.' It is not a question of either God's activity or human activity, but of God's activity and human activity as the proper response to this.

For Buchan, the shape of this proper response is determined by the moral teaching found in the Bible and the mainstream Christian tradition, and everyone has the choice to either behave in a way that is in line with this teaching, or to fail to do so.

Today we live in a world of identity politics in which people are divided into sharply defined groups who are collectively victims or villains, oppressed or oppressors. Buchan, however, in line with the Bible, teaches us that everyone, regardless of their class, race, nationality, or sex, is an individual with a personal calling to respond in morally appropriate ways to the situations in which God's providence has placed them.

Thus, in his novels the 'Gorbals Die-hards,' the members of an informal scout troop from the Glasgow tenements are called to make the right choices in their situation, and exactly the same is true of Sandy Arbuthnot, Lord Clanroyden, who inherits an ancient Scottish estate and title following the death of his father and elder brother. Their social circumstances are poles apart but the basic choices before them are exactly the same.

Today we are constantly told that our key goal in life should be self-fulfilment. By contrast, Buchan teaches us that the key goal in life should be service. For him the point of our existence as human beings is to 'make our souls' and we do this by serving God in the service of others, even if this means following in the footsteps of Jesus by sacrificing our lives on their behalf.

Two very different characters in his novels illustrate this theme.

The first is Peter Pienaar, a Dutch South African game hunter with a criminal past who ends up in the Royal Flying Corps in World War I but is invalided out after being shot down. During his recuperation he rediscovers his childhood faith and although he has the choice of a peaceful retirement, he instead sacrifices himself on one last suicidal flight to protect the British army during the German offensive in March 1918.

Buchan describes him in terms of John Bunyan's character Mr-Valiant-For Truth from The Pilgrim's Progress and applies to his death the words of Bunyan describing Pilgrim's entry into the celestial city, 'So he passed over, and all the trumpets sounded for him on the other side'.

The second is Sir Edward Leithen, the hero of Buchan's final novel Sick Heart River. Leithen is a scholar, lawyer and politician who has served as the Attorney General. Faced with the news that he has a fatal illness as a result of being gassed in World War I, Leithen determines to 'die standing' and so goes off to the wilds of Canada to track down a prominent Canadian who has gone missing and needs to be brought home. Leithen successfully completes his mission and is offered the opportunity of being cured of his illness and living out his life in comfort.

However, he too rediscovers his Christian faith, and so instead he lays down his life working with a French Catholic missionary to save a village of Hare Indians who are in danger of being wiped out through famine, cold and despair. Buchan describes Leithen's end with the word of Jesus, 'Whoever would save his life will lose it, and whoever loses his life for my sake will find it' (Matthew 16:25).

The final lesson Buchan teaches us is how to view the enemy in a time of war. For Buchan, war in a just cause is sometimes necessary as part of the Christian battle against evil, but he nevertheless insists that standing for good against evil also means that we must set aside any desire for revenge and view the enemy with Christian compassion, whatever atrocities they commit, and whatever responsibilities they have for the war.

Thus, in Greenmantle his hero, Richard Hannay, is rescued by the wife of a woodcutter while lost on an undercover mission in Germany in World War I. Her husband is away in the German army fighting the Russians and she and her children are poverty stricken and have very little food. However, out of Christian charity she unhesitatingly offers food and shelter to Hannay, who is suffering from a bout of malaria, and her example changes Hannay's attitude completely:

'When I saw the splintered shell of Ypres and heard hideous tales of German doings, I used to want to see the whole land of the Boche given up to fire and sword. I thought we could never end the war properly without giving the Hun some of their own medicine. But that woodcutter's cottage cured me of such nightmares. I was for punishing the guilty but letting the innocent go free. It was our business to thank God and keep our hands clean from the ugly blunders to which Germany's madness had driven her. What good would it do Christian folk to burn poor little huts like this and leave children's bodies by the wayside? To be able to laugh and to be merciful are the only things that make man better than the beasts.'

In the same novel, Hannay is introduced to the German Emperor Wilhelm II, generally regarded in Britain at the time as a simple one-dimensional villain, in the same way people regard President Putin today. However, Hannay discovers that the emperor is a man in pain 'who slept little and whose thoughts rode him like a nightmare.' The emperor is tormented by the knowledge of the war he has unleashed and the millions dying as a result.

Hannay comments, 'I felt that I was looking on a far bigger tragedy than any I had seen in action. Here was one who had loosed Hell, and the furies of Hell had got hold of him.' The point Buchan is making is that while the emperor has moral responsibility for the war, he is still a human being, and so the appropriate Christian response to his mental torment is not satisfaction but pity, because what is happening to him is tragic.

These five lessons that Buchan teaches are ones that those of us who are Christians still need to learn today. He was a great Christian writer, and we need to learn from his wisdom to navigate our way through the challenges we face.

Martin Davie is a lay Anglican theologian and Associate Tutor in Doctrine at Wycliffe Hall, Oxford.