Britain needs some of Aslan's 'deep magic' to reimagine its future, says Archbishop of Canterbury

Britain needs to 'reimagine' a new set of values to face a radically different future, according to the Archbishop of Canterbury.

In the first of his Holy Week lectures at Canterbury Cathedral last night, Archbishop Justin Welby drew on the biblical story of Mary anointing Jesus' feet with perfume to appeal to 'the extravagant, gratuitous love that is the Kingdom of God and which when even palely absorbed into human society is the root and flower of human flourishing'.

The Archbishop of Canterbury delivered the first of his Holy Week lectures at Canterbury Cathedral last night.

He referred to the combination of the huge economic shock from the 2008 Great Recession and the decision to leave the European Union. 'The task of reimagination of our future values is far more complicated than after 1945, and the result is that the process will be one of generations not of a few years,' he said.

He said that by contrast with previous historic periods, 'Today's society is faster, more complicated, more independent and more confused. Religious observance is far weaker, yet where it occurs, far more committed. Political life is very complicated, and nationalism and populism are strong, the former especially in Scotland. The very existence of the UK is seen as at risk.'

However, he said: 'Our deepest narrative of a good society in this land is the Christian one. It is an ever growing story of how the great virtues and benefits of gracious love are lived out in the hard pounding of a changing world. Moments of great change require us both to keep in contact with the deep narrative, and also to express what that means in new ways.'

The choices Britain faces today, he said, had to take account of increased secularism and 'multi-ranging values' as well as a plurality of religions. But he warned of the danger of a 'rootless and self-protective society without generosity, arising from a lack of confidence of what it is to be British'.

Welby drew on CS Lewis' idea of 'deep magic' in his children's novel The Lion, the Witch and the Wardrobe, saying: 'In such deep values lies the force which drives us forward and corrects our errors. When the deep values are fractured then all hell breaks out. The deep values are those which set our boundaries and cause us instinctively to say "this is not right", or "that is wrong".'

He warned of 'an absolute lack of foundations to deal with numerous faiths, different cultures, globalised economies, and above all, a world in which all values from all over the world confront us more rapidly and effectively than ever before', and suggested that Christian faith could be a 'model and example' of 'a generous and hospitable meta-narrative within which competing truths can be held, a narrative which has the spirit of Mary, extravagant, gracious, beautiful'.

Welby also revealed he is writing a book on British values, to be published next year.