Writing on his Patheos blog, called Sic et Non, Daniel C. Peterson points us to two important articles about the hollowing out of America’s mainline churches. 

Latter-day Saint noted social scientist, Stephen Cranny wrote this article for the Deseret News.

Liberal-leaning Churches are Shrinking Compared with Many Conservative Churches

I enjoy occasionally taking my children to various churches to expose them to diverse religious experiences. Recently, our interfaith journey led us to two Episcopalian services that were both markedly similar yet clearly different: the service at a large, stately church in our area, the headquarters of one of the most prominent mainline Protestant denominations in the United States, and a lively gathering across the river at a more conservative group that splintered off from the mainline Protestant denomination.

At the former, known for its grand architecture and progressive stance on contemporary social issues, the congregation was dignified yet notably older. At the second location, a congregation buzzed with energy. Young families filled the pews, cutting-edge media accompanied a crisp, not missing-a-beat homily from a relatively young preacher.

If not obvious on the surface of these two services, hiding underneath are the scars from a painful ecclesiastical civil war that rent the denomination in two. As the larger denomination became more liberal on social and theological issues, the more conservative elements became nervous, and eventually split off to form a more conservative variation.

This scenario has played itself out a number of times: two denominations with the same historical roots start moving in different directions and drifting apart. For example, the United Methodist Church is currently undergoing a painful divorce over sexual and gender minority issues.

When a schism like this happens, the differing fates of the two denominations provide an interesting compare and contrast. Conventional wisdom would hold that the branch that is more self-consciously socially progressive would attract younger parishioners, while the more conservative group clinging to tradition would be more moribund. Yet matching our family’s experience of these two worship services, in many cases this is not what the available statistics suggest at all.

Cranney points out:

As I have pointed out previously, I have lived for years on the East Coast, where there are many churches (especially mainline ones) shuttered and converted to other uses (or sometimes just abandoned and rotting like an open sore). I always feel a sharp pang of morose depression when I pass by them.

However great it may be that the private school now using that location has super neat architecture, the fact is these earlier people sacrificed to build these structures as monuments to God, not monuments to Montessori. These used to be thriving communities full of life and vivacity, with thousands of personal memories and stories; where children once played, people spoke to God, young lovers flirted, and lifelong marriages were solemnized. And now their windows are shattered and their dusty halls are silent.

Read more here. https://www.deseret.com/faith/2024/07/29/liberal-churches-are-shrinking/

What Brother Cranney has to say in his article reminds me of a still rather famous 1972 book — still famous in certain circles, anyway — by the late Dean M. Kelley, Why Conservative Churches Are Growing: A Study in Sociology of Religion.  Here is a good one-paragraph review of Why Conservative Churches Are Growing that was posted on Amazon.com by one David Franz back in 2006:

In 1969 Peter Berger told the New York Times that religious people would soon be huddled together in little enclaves, surrounded by a sea of secularity. In doing so, he was simply making explicit the philosophy of history implicit in social theory since its founding. According to this philosophy, Christianity became Protestant, then liberal Protestant, then vaguely and privately spiritual, moving inevitably towards secularism. In the 60s and into the 70s the data on American religion seemed to support this story – at least in mainline churches. First published in 1972, this book directed attention to the surprising and theoretically problematic fact of growing conservative churches, precisely those churches that were most demanding and seemingly ill-equipped for the modern world. As secularization and modernization theory crumbled with the resurgence of conservative religion in public life in the US and around the world (see Jose Casanova’s Public Religions in the Modern World), it became clear that conservative religion was not going away quietly and that social science had been dead wrong. Kelley was among the first to recognize that there was something mistaken with social science’s predictions of a secular future. His book was part of a dramatic, if belated, recognition among scholars that lots of Americans find conservative, strict Churches profoundly attractive.