'What do these stones mean?' As you come into this Abbey by the West Door, you pass underneath a row of carved figures representing the martyrs of the twentieth century, placed there just a few years ago to mark an era that had seen a greater number of people killed for their faith than in the whole of the preceding two thousand years. They speak of an age of unprecedented levels of slaughter, on the grounds of race and class as well as religion. The twentieth century witnessed two of the greatest tyrannies humanity has ever endured, the terrible regimes of Nazism and Communism; all the resources of modern science and administration were put at the service of systems that enslaved and murdered and humiliated millions. Anyone tempted to think that modern knowledge and skill will of themselves liberate human beings from violence, might do worse than reflect on what those stones mean at the entrance to this building – as they might reflect at Yad Vashem, the Holocaust Memorial in Jerusalem.

Today of all days, we need no reminder that the spirit of murder and humiliation is still abroad. As Your Majesty reminded us on Friday, there is a generation of people for whom the sight of a devastated, bombed London will bring back harsh memories; memories not only of physical damage but of the sense of obligation to go on resisting the venomous tyranny responsible for it.

Yet what seemed the greatest and best defended tyrannies of all have vanished, the systems that controlled whole empires and vast armouries. The twentieth century may tell us that we have nothing to be complacent about in the recent history of humankind; but it also tells us that there is nothing inevitable about tyranny. People have resisted, lies have been exposed; in all sorts of different ways, men and women have risked and surrendered their lives so that the truth might have witnesses.

Most of those among you who have seen active service will probably find the idea that you have been witnesses to the truth a bit extravagant – just as extravagant or embarrassing as the tributes paid, and paid with the greatest sincerity, to your personal courage and sacrifice. But what we celebrate today – what we celebrate in the records of the last war and of the last week in London – is precisely that instinctive, undramatic awareness of the difference between truth and lies that makes people commit their best energies and risk their lives and safety in resisting oppression and deceit. We celebrate too the mysterious fact that when those best energies are mobilised, it is as if they open the door to extra resources of strength. Because from a human point of view, victory against Hitler was no foregone conclusion, any more than was the fall of the Soviet Empire. But hundreds of thousands worked – and suffered – in all kinds of ways to keep the truth alive; and somehow truth proved strongest after all.

More perhaps than any war for centuries, the conflict that ended sixty years ago had for us in Britain the clear character of a moral struggle. It had been very hard to preserve any such conviction through the weary years of the First World War; but there was in the last war some sense of fighting for more than the security of one country. For so many it was genuinely a 'people's war', an enterprise involving the whole national community in the defence of something greater than just the national community alone. And it took the war to prompt the international community to take all those dramatically significant steps towards a world of recognised rights and liberties represented by the United Nations and its agencies. You cannot understand the impulse of this without recognising the passion that was generated during the darkest days of the war, a passion to see human dignity vindicated after an age of insult and disfigurement. That passion will have been rekindled in recent days. In that sense, this service is a fitting response to the terror of the last week and a true complement to all that has been going on recently around the G8 meeting to witness to human dignity.

The willingness to work for the truth unlocks something beyond our own resources. It is not all about military might and strategy, nor even all about the more visible sorts of courage and endurance in conflict. That is why we remember not only the soldiers but those who laboured at home, whose countless mundane and routine actions also made resistance possible and so witnessed to truth; and not only those who laboured but those who suffered too. Among the figures on the West Front here are two who might well sum up the cost of witness and the lasting strength it reveals. Dietrich Bonhoeffer, German pastor and teacher, hanged in prison in 1945 just before the end of the war, had faced an appalling choice in 1939. He could have stayed in the US where he was a visiting scholar. After all, he already had a bad reputation with the regime, broadcasting critical talks on radio until he was silenced, organising a secret programme for training dissident pastors until that too was stopped. He could have kept up his criticism and his encouragement from a distance and saved himself to help in the reconstruction of a new church and nation after the war.

But he chose to return. He could see no alternative to being with his people at this time of crisis. He had to find out how to be loyal to Germany when Germany seemed determined to betray both God and humanity, and he believed he could do it only by sharing their suffering and taking risks for them – risks that included his involvement in directly subversive activity. Again and again, attempts at subversion within Germany failed. But his witness, in his letters from prison, in the countless lives he inspired, in his death, was surely something that opened up those deep resources beyond our imagining just as much as the work of those who resisted in other, apparently more successful, ways.

The second figure is that of a far less well-known man – Lucian Tapiedi, a villager from Papua-New Guinea who had become a teacher and evangelist in the highlands. When the Japanese invaded the country in 1942, there was just enough time for the missionaries and their helpers to withdraw. But their bishop urged them not to do so; they stayed with the people whom God had given them to care for, and over three hundred mission workers were killed in cold blood during the invasion. Lucian was among them: he told his native colleagues to take their wives and families to hide in the jungle. 'I am single; I'll stay with the fathers and sisters; it doesn't matter if the Japanese get me.'

Two such different men, in the two great theatres of the war; one a sophisticated, complex European intellectual, one a village teacher. But both were loyal men, loyal to the truth, loyal to a God who works even through suffering and defeat to demonstrate his unbounded compassion, loyalty to a humanity that God has loved and valued and which must therefore never be dishonoured.

'What do these stones mean?' For Joshua and the people of Israel they meant that God was faithful, that God was loyal to them. For us, looking at the memorials of those witnesses to truth, they mean that God's faithfulness is made visible in lives that are loyal to him and to his beloved human children. We thank God for all who have been loyal in this way – who have seen the lie in terror and murder, and have risked their safety and their lives for the truth on many different kinds of battlefields and in many different sorts of danger. Knowingly or not, they have witnessed to the faithfulness of God and to what God purposes for human beings. They have touched what Jesus calls 'blessedness' – that being in tune with the truth that no violence or failure can destroy. They let the light of truth shine before the world. We pay tribute today to a generation who found the courage to witness, soldiers, civilians, martyrs together; may God help us in this generation and in the future to hold up the same light with the same faithfulness against the same powers of darkness – living stones, living signs of blessing.

© Rowan Williams 2005