Rowan Williams has this to say:

“It is not true that large numbers of people reject Christian faith –  if by ‘reject’ we mean that they deliberately consider and then decide against it. They are imperceptibly shunted towards a position where the ‘default setting’ is a conviction that traditional Christianity had nothing much to be said for it. People who have settled down in this position are not likely to be much moved by argument: they need to be surprised into a realization that they have never actually reckoned with what Christianity is about” [The Lion’s World: A Journey into the Heart of Narnia, 2012, pp.14-15].