The trend lines, at least in the short-term, haven’t been looking good for the future of faith.
You can hardly blame people for being pessimistic, not when surveys of many countries show the importance of God declining and religion’s influence shrinking, especially since 2007. Not when religious ‘Nones’ are now the largest single group in the U.S (as of 2024) and the fastest growing religious category.
Younger generations are also less religious than older generations — with 46 out of 106 countries in Pew research between 2008 and 2018 showing people age 40 and older more likely to say religion is very important to them. (The researchers found 58 countries showing no difference between older and young generations, with two countries, Ghana and the former Soviet republic of Georgia, showing young people with more interest in faith). There’s also a 10-point difference between younger and older generations’ religious identification in an average European country.
Given all this, how could you not simply conclude that the future of global religion is dire? Because of the children, that’s how. That’s one of the most interesting conclusions in the recent Wheatley report, “The Tides of Religion: Leaving, Staying, and Returning to Faith.”
As the report makes clear, a comprehensive picture of religious disaffiliation in America and throughout the world is necessarily complex — with a wide variety of factors that shape changing faith trajectories over time. Potentially lost in this complexity is one especially fascinating influence that packs an oversized punch, especially given its diminutive size.
A hidden confound: The baby factor
Fixating on immediate, real-time measures naturally leads to conclusions shaped by short-term measures. But looking out long-term, there is good news for faith on the horizon, much of which centers on the oversized impact of one smallest variable of all.
“Global trends indicate that the world is actually becoming more religious as birth rates in highly religious regions surpass those in increasingly secular areas,” the report states.
According to the Wheatley team, Stephen Cranney, Justin Dyer, Sam Hardy, Paul Lambert and Loren Marks, this baby factor plays a significant role that hasn’t been fully appreciated. Simply put, religious communities catalyze more marriages and more children, while secular populations are failing to replace themselves.
The declining birthright throughout much of the world has been getting more attention in recent years. What’s far less talked about are the places in the world where the birth rate is going up — not down — and why that is.
“In order for a country to maintain a stable population without growth or decline,” the Wheatley team notes, “each woman must have an average of 2.1 children.” You can see that “replacement rate” marked with a dotted blue line on the chart below, comparing overall fertility rate in a country with the percentage of people who say religion is important. There are clear patterns in countries which fall above or below that line.
The first pattern to jump out for most people is poverty vs. wealth. Poor societies tend to be religious, the scholars note, but the fact that “within the same country more religious people have more children” means the difference can’t be explained by socioeconomic differences alone, instead, suggesting that “differences in birth rates between countries is in large part due to differences in faith.”
This is the “clear pattern” that emerges in the chart, according to the Wheatley team. “Countries that reach this crucial replacement rate are, almost as a rule, religious, with solid majorities considering religion very important.”
More faith, more marriages, more babies
“Research consistently shows that religious people have more children and express a desire for larger families,” they continue. “This relationship between childbearing and societal religiosity is apparent on a global scale ... This desire for more children is seen among individuals across various religious dimensions, including among otherwise nonreligious people who believe in God.”
“The countries that are more religious are having a lot more babies,” Cranney recaps to Deseret News. “That has significant effects for people who are projecting what religion is going to look like in 50 years.”
Those countries where religious influence is dwindling, by contrast, are experiencing a fertility drop. That includes the United States, where the authors note “childbearing is already below replacement levels.”
The decline in religion translates into “lower marital rates,” these scholars report. “Therefore, as the United States becomes more secular, we can expect a growing number of unmarried and never-married individuals.”
“Secular societies are simply not replacing themselves,” the Wheatley team sums up. “Apparently humanity’s survival requires at least some religiosity.”
“Secular societies are simply not replacing themselves. Apprently, humanity’s survival requires at least some religiosity.”
— 'The Tides of Religion': Leaving, Staying, and Returning to Faith.
Projections of growing religiosity in the global population
Pew associate director of research, Conrad Hackett and colleagues published an extensive analysis on this question in 2015, noting that those expecting the religiously unaffiliated to grow in their percentage of the future global population “overlook the impact of demographic factors.” After analyzing more than 2,500 data sources, they concluded: “The religiously unaffiliated are projected to decline as a share of the world’s population in the decades ahead because their net growth through religious switching will be more than offset by higher childbearing among the younger affiliated population.”
This means that as the world population grows, “the number of agnostics and others who don’t affiliate with a certain religion shrinks as a percentage of the global population,” wrote Jeanna Bryner at the time, a managing editor for Scientific American, summarizing projections for 2050.
Demographers Todd M. Johnson and Brian J. Grimm likewise projected in 2013 the “continued resiliency of world religions into the future” in an analysis that looked out as far as 2050.” They stated that the “strongest evidence” available “shows that the global trend of religious resurgence is likely to continue into the near and, perhaps, distant future.”
This kind of a projection is a stark contrast to the strong secularization many witness in their lives today, Wheatley scholars acknowledge. But this can happen with other statistical paradoxes, they explain, “where trends that appear in several groups of data actually reverse when the datasets are combined.”
In this case, “although most countries are becoming less religious on an individual level, the global population is increasingly concentrated in more religious regions, particularly in sub-Saharan Africa, where birth rates are higher. As a result, despite the trend that most countries are becoming less religious, the world is in fact becoming more religious in the aggregate.”
Different fertility and disaffiliation rates across faiths
Thus, “the long-term growth of different religions is not based solely on people leaving or joining but also on birth rates of their adherents,” the Wheatley team summarizes. Whereas “some traditions such as mainline Protestantism are simply having fewer children,” they write, there are still “higher-than-average birth rates” among other faiths, including members of The Church of Jesus Christ of Latter-day Saints.
It’s also worth noting, Cranney tells Deseret News, that “it’s not the more left leaning churches that are retaining the youth” — something he’s written about here previously. This report again points to the fact that deconverts disproportionally come from the liberal side of the faith spectrum.
“So the idea, again, that religions need to downplay truth claims or liberalize to survive,” Cranney says, “isn’t really supported by the data.”
‘Population momentum’
“Society and demographic stability,” are strongly influenced by “religion’s influence on individual behavior,” these scholars note — and not just behavior in the present era. Whatever the current differences in birth rate, they explain, it’s also the case that larger families in the past lead to more growth right now due to a phenomenon called “population momentum.”
This is a kind of “built in” population growth centered on how many young people are positioned by a community to be moving into childbearing years. According to population expert Pam Wasserman, this allows a country’s population to keep “growing for another 70 years” even after fertility dips below replacement levels.
The Wheatley report summarizes, “Some of the current growth in The Church of Jesus Christ of Latter-day Saints stems from its past generations with larger families.”
All this, Cranney summarizes, pushes back on the idea that “religion is inevitably declining” and the “general secularization theory that religion is going to inevitably decline until it is completely dead.”
Maybe, then, global religion is more like your favorite sports team that looks so far behind in a game that you start to give up on any chances of winning. But to the shock of all onlookers, they somehow manage to come out on top in the end.