“We who defend Christianity find ourselves constantly opposed not by the irreligion of our hearers but by their real religion. Speak about beauty, truth and goodness, or about a God who is simply the indwelling principle of these three, speak about a great spiritual force pervading all things, a common mind of which we are all parts, a pool of generalized spirituality to which we can all flow, and you command friendly interest.
But the temperature drops as soon as you mention a God who has purposes and performs particular actions, who does one thing and not another, a concrete, choosing, commanding, prohibiting God with a determinate character. People become embarrassed or angry. Such a conception seems to them primitive and crude and even irreverent. The popular ‘religion’ excludes miracles because it excludes the ‘living God’ of Christianity and believes instead in a kind of God who obviously would not do miracles, or indeed anything else.”
From: The Business of Heaven: Daily Readings From C.S. Lewis, page 31 (January 22 reading, titled “When the Temperature Drops”