Good read here. It's clear that Michael Horton, the Calvinist apologist who did the interviewing, has read Christian Smith's book on Secularism, where he apparently argues that Secularism was carried out by special interest groups, rather than being an organic development. The "believing without belonging" comment by Horton was drawn from Grace Davie's book by that title.
If you, dear reader, are curious about Horton, I would like to quickly poison you against him by offering you this review, which I happily found on Amazon.com, covering the content of his "Systematic Theology", which is supposed to be the biggest ST event of the past 100 years or so, if we are to believe the billing. We should not.