For several decades now, I have been hearing pollsters -- with organizations on the left, right and in the middle -- asking some very similar questions about trends on the left side of the marketplace of ideas that is American religion. In fact, they have often, been asking precisely the same question.

That doesn't happen very often. So when it does, I think that it behooves those of us who report and write about religion to pay attention.

Here's the key question: If more and more Americans are moving toward liberalism on questions of faith and morality, then why are the membership statistics continuing to spiral down in doctrinally liberal churches?

That question came up again this week in our "Crossroads" podcast, when host Todd Wilken and I talked about the heritage of research done by the late George Gallup, Jr., and how it related to a new LifeWay Research survey -- the "Theological Awareness Benchmark Study" conducted for Ligonier Ministries of Orlando, Fla. Click here to listen in.