An article in the web Out of Ur lays out the research of Willow Creek under a controversial title
October 18, 2007 Willow Creek Repents? Why the most influential church in America now says "We made a mistake."
The chart shows that people start well at Willow but "Hit walls" of problems crash, burn and drop out.
http://blog.christianitytoday.com/outofur/archives/2007/10/willow_creek_re.html The writer says it this way:
When I read the comments on the post I could see American Christianity writ small. Almost every person has an axe to grind. Several were wounded that the title seemed to attack Willow Creek. Others are upset that few churches are preaching "Expository sermons that go line by line through the text," because if they did we would not have so many immature Christians. (It occurred to me that Jesus would be considered a complete failure if He were judged by that standard.)
Here are my own comments:
Thanks to WC for a gutsy look at themselves. Think stages of spiritual growth just like stages of academic and emotional growth. WC has done well with Pre Believers and New Believers. Not so well with folks with spiritual problems who Stalled and not well with the older, more committed types. (See the chart above for those who stalled.)