The Religion News Service column “Flunking Sainthood,” as the title indicates, expresses the outlook of liberal Latter-day Saints. But author Jana Riess, who comes armed with a Columbia University doctorate in U.S. religious history, is also interesting when writing about broader matters.

Her latest opus contends that two standard theories about big trends in American religion are too simple and therefore misleading. Her focus is the rise of religiously unaffiliated “nones” to constitute 39 percent of “millennials” from ages 18 to 29. The Religion Guy more or less agrees with her points but adds certain elements to the argument.

So, theory No. 1: Though Riess doesn’t note this, this concept was pretty much the creation of the inimitable Dean M. Kelley (1927–1997) in “Why Conservative Churches Are Growing.” This 1972 book was electrifying because Kelley was a “mainline” United Methodist and prominent executive with the certifiably liberal National Council of Churches. (His expertise on religious liberty gave the NCC of that era a major role on such issues.) 

Under this “strict churches” theory, religious bodies that expect strong commitments on doctrine and lifestyle from their adherents will prosper because this shows they take their faith seriously, and  they carefully tend to individual members’ spiritual needs. By contrast, losses characterize more latitudinarian (Don’t you love that word?) denominations such as those that dominated in the NCC.

Kelley’s scenario proved keenly prescient, since white “mainline” and liberal Protestant groups were then just beginning decades of unprecedented and inexorable declines in active membership and over-all vitality. The Episcopal Church, for one example, reported 3,217,365 members in 1971 compared with 1,951,907 as of 2010. So much for left-wing Bishop Jack Spong’s 1999 book “Why Christianity Must Change or Die.” Statistics have been even more devastating with groups like the United Church of Christ and the Church of Christ (Disciples).

Now comes Riess to announce that scenario is “crumbling” because some strict conservative groups like the Southern Baptist Convention (SBC) have also begun declining in recent years while others, e.g. her own Latter-day Saints (LDS) or Mormon Church, still grow but at more sluggish rates.

That’s accurate, important, and yes it tells us factors other than strictness are at play.