Jim Collins's recent book Good to Great has inspired both business and church leaders. It is a study of 28 good companies that became great as measured by their outperforming the stock market by at least seven times over a 15-year period. Countless companies are now applying the "hedgehog concept" and other principles from the book, trying to become similarly great.

Likewise, many churches are seeking to become great churches. Entire ministry industries exist to help that process—from fund raising, to church building programs, to worship resources, to programming. And in nearly every community, there's at least one great church, as measured by numbers and facilities.

But large churches discover a troubling secret. Size alone isn't good enough. Great or small, churches need something more than bigger numbers.

Bob Buford, author of Half-Time, notes that at midlife, many people discover they've built their lives around "success" only to find it empty. So they reinvent themselves to build the ...