In 1972, sociologist Dean Kelley wrote a book entitled Why Conservative Churches are Growing. Kelly, an executive with the mainline and ecumenical National Council of Churches, wanted to know why mainline Protestant denominations were declining in membership and conservative evangelical churches were experiencing rapid growth. He concluded, among other things, that churchgoers wanted to belong to congregations that made demands on their lives. Mainline churches, Kelly argued, were so concerned about image, courtesy, cooperation, and being non-dogmatic that they were failing to attract churchgoers who wanted their churches to be more than community centers. Kelly issued a stern warning to his fellow mainline Protestants: their watered-down version of Christianity was a recipe for disaster.
Evangelicals have been touting Kelly's findings for years. For many of them, Why Conservative Churches are Growing provides sociological evidence for what they knew all along—the Holy Spirit is blessing evangelical churches because they have remained true to the tenets of orthodox Christianity, including the inerrancy of the Bible and the necessity of a born-again-style conversion. During the 1920s the Protestant mainline may have won control of the denominations, but they were unable to win the souls of ordinary Americans.
But before evangelicals jump to theological conclusions about why they have been so successful over the last fifty years, they should read University of California-Berkeley historian David Hollinger's recent presidential address to the members of the Organization of American Historians. (It has been published in June 2011 issue of The Journal of American History under the title "After Cloven Tongues of Fire: Ecumenical Protestantism and the Modern Encounter with Diversity).
Hollinger makes several provocative arguments about twentieth-century evangelicalism and mainline Protestantism, but the most interesting part of his essay is his take on why, since the 1960s, mainline churches have declined and evangelical churches have flourished.
According to Hollinger, the rise of evangelicalism as a religious movement and the decline of ecumenical Protestantism are best explained through fertility. It seems that mainline Protestant parents did not have as many children as evangelicals. For example, during the great "baby boom" of the post-war years, Presbyterian couples had an average of 1.6 children, while evangelicals had an average of 2.4. Moreover, these children, upon reaching adulthood, did not become members of the churches or denominations in which they were raised. Evangelicals, on the other hand, tended to have large families and proved to be more successful in keeping them in the evangelical fold. Today's mainline churches are filled with senior citizens and retirees, while evangelical congregations are flooded with young families.
Hollinger's theory makes sense. In the mid-twentieth-century, mainline Protestants tended to be more educated than evangelicals, and studies show that educated people in post-war America tended to have less children than those without a formal education. Mainline Protestant denominations embraced birth control well before it was an acceptable practice in evangelical circles. In addition, anecdotal evidence suggests that evangelicals in this era were more effective than mainline churches at youth ministry. To put it simply, evangelicals have succeeded where mainline Protestants have failed because there are more of them.
I am sure there are many evangelicals reading this column who at this point are shaking their heads. They wonder how a Christian historian who writes a column called "Confessing History" can even suggest that the evangelical church has blossomed in the last several decades for any reason other than a spiritual one. In other words, the mainline Protestant denominations have been unfaithful to biblical truth while the evangelical churches have managed to stay the course. As a result, evangelicals have mega-churches and mainline Protestants do not. (Of course, such a view is based on the idea that church growth is the mark of a healthy church. Yet didn't Jesus say something about a "narrow road?")
Perhaps there is some way to explain this spiritually. I will leave that to the theologians. But I also think that there is much to learn from theories like the one Hollinger proposes. We know from the Scriptures that the will of God will be done "on earth as it is in heaven," but on this side of eternity we continue to "see through a glass dimly." Evangelicals must have faith in God's providential ordering of the universe, but should not dismiss the social and cultural reasons why His creation behaves in the way that it does Historians are not in the business of explaining the will of God in human history, but they do give us a better sense of why humans act in the way they do. And such information might, at times, enable the Church to more effectively advance its mission in the world.