Modeling the decline of American Christianity

What does America look like if the decline in Christian belief continues? What might this mean for higher education?

I’ve been tracking this religious trend for a while (2021, 2019, 2017). Today I’d like to follow up with a new Pew study, which models several possible scenarios for American religious transformation. As a futurist who tracks religion, but is not a religion scholar, I found the work fascinating and useful. It’s a good example of evidence-based trend analysis, extrapolation, and scenario development.

The main focus of the study (Stephanie Kramer et al) is people switching religions. In the American context, or in the view of Pew, this means a person being born in a Christian faith, then leaving for something else, including to a status of no formal religious affiliation. “Since the 1990s, large numbers of Americans have left Christianity to join the growing ranks of U.S. adults who describe their religious identity as atheist, agnostic or ‘nothing in particular.’”

The report starts from a 2020 baseline, then extrapolates several scenarios based on different forms the decline trend might take. That baseline looks like this:

The Center estimates that in 2020, about 64% of Americans, including children, were Christian. People who are religiously unaffiliated, sometimes called religious “nones,” accounted for 30% of the U.S. population. Adherents of all other religions — including Jews, Muslims, Hindus and Buddhists — totaled about 6%.

From that baseline, how might America change if the observed dis-Christianization continues? To explore this, Pew offers several models of Christian affiliation in decline, depending on how the trend plays out:

You can see different dates when Christian affiliation falls below one half of the population, unless the “no switching” change occurs.

At the same time, the proportion of “nones” (“People who are religiously unaffiliated”) rises to different levels, again depending on how that trend takes shape: