Stark blames the rise of modernist theology and the transformation of mainline churches into centers for progressive political action. Whatever the reason, evangelicals no longer stand on the periphery, outside the prestigious mainliners. “The periphery is the mainline” now, says Stark, “and the mainline is the sideline.”

When a leader in the National Council of Churches wrote in 1972 that the mainline churches were shrinking while conservative churches were growing, he was furiously criticized. Yet Dean Kelley’s thesis has gone from controversial to confirmed in less than 40 years.

Witness the 2011 Yearbook of American and Canadian Churches, which the National Council of Churches released in February. The yearbook presents information on 227 church bodies, on the basis of data collected and submitted (or estimated in the case of uncooperative groups) over the previous two years.

The Catholic Church remains the largest religious body by far, with 68.5 million members, followed by the Southern Baptist Convention, with 16.2 million. Yet the most striking figures in the 2011 yearbook are the continued declines among mainline denominations.

Among those who updated their membership totals, the biggest gainers were the Jehovah’s Witnesses and Seventh-Day Adventists, with annual increases of 4.37 percent and 4.31 percent. The Mormon church (LDS) saw an increase of 1.42 percent, and the Catholic Church and Assemblies of God came in fourth and fifth, with 0.57 and 0.52 percent growth, respectively.

The five biggest drops in membership were among mainline denominations. The 2011 totals dropped for the United Church of Christ by 2.83 percent, the Episcopal Church by 2.48 percent, the Presbyterian Church (USA) by 2.61 percent, the Lutheran Church (ELCA) by 1.96 percent, and the United Methodist Church by 1 percent.

Yet the news gets worse with a longer frame of reference. Membership in the United Methodist Church has declined by over 600,000 members, or over 7 percent, from the 2001 to the 2011 yearbooks. The Presbyterian Church (USA) has lost nearly 800,000 people, or over 20 percent of its membership, in that span.

Rounding out the top 25 are mostly Baptist, African-American, and Pentecostal denominations. As renowned sociologist Rodney Stark told me recently, mainline denominations have been in decline for many generations, yet the decline in their “share” of the American religious marketplace was masked until the 1960s by general population growth. Stark blames the rise of modernist theology and the transformation of mainline churches into centers for progressive political action.

Whatever the reason, evangelicals no longer stand on the periphery, outside the prestigious mainliners. “The periphery is the mainline” now, says Stark, “and the mainline is the sideline.”

© Copyright 2011 World Magazine. Used with Permission