While talk of Christianity's decline needs qualifying (the Christian faith continues to expand at a global level) it is incontestable that the faith falters in its Middle Eastern and European heartlands, meaning not just the retreat of religion from the public square - external hostility, and a weak response from ecclesiastical ranks, are mutually reinforcing - but also the thinning out of religion itself.

Public spaces have been largely evacuated of Christian presence as the state's ability to meet people's material needs has increased. Different dynamics are at work in various European countries - notably France, Germany and Spain - but the family resemblances are substantial. The Church has been left asking what it still has to talk about as the credibility of its own metaphysical claims has been diluted.

Many people grant the positive role played by Europe's Christian heritage in raising us to the branches on which we now perch, but still think that the ladder can be kicked away. People with very little cultural memory of Christianity begin to ask Why should we care?And Is belief in God credible in the first place? Yet the secularist still cuts corners in inferring that the Church has done its job and can now fade away.

Based on solid reportage and canvassing a broad range of views - giving due weight both to genuinely positive aspects of progressive politics and ways in which unaccountable ecclesiastical power needs to be challenged - Shortt nevertheless argues that the Churches are seriously underselling themselves. Representing the largest source of social capital on earth, they have a much stronger message than they themselves often recognize. Of course, Britain and other European countries are multicultural. Theocracy and other forms of authoritarianism should be shunned. But Christian values represent humanity's best hope. Clerics and other representatives should be saying so far more robustly.