Fewer than half of Americans may be Christian by 2070

New report projects a future where Christianity, though diminished, persists, while non-Christian faiths grow amid rising secularization.

(Rick Egan | The Salt Lake Tribune) A worshipper attends a Spanish Mass at the Sacred Heart Catholic Church in Salt Lake City in 2021. New research shows Christians could make up less than half the U.S. population in 50 years.

America has long prided itself on being a country where people can choose whatever religion they like. The majority has long chosen Christianity.

By 2070, that may no longer be the case. If current trends continue, Christians could make up less than half the population — and as little as a third— in 50 years. Meanwhile, the so-called nones — or the religiously unaffiliated — could make up close to half the population. And the percentage of Americans who identify as Muslims, Jews, Hindus, Buddhists and other non-Christian faiths could double.

Those are among the major findings of a new report from the Pew Research Center regarding America’s religious future — a future where Christianity, though diminished, persists while non-Christian faiths grow amid rising secularization.

Researchers projected possible religious futures for the United States using a number of factors, including birthrates, migration patterns, demographics like age and sex, and the current religious landscape. They also looked at how religion is passed from one generation to another and how often people switch religions — in particular, Christians who become nones, a number that has been increasing in recent years.

They projected four scenarios, based on differing rates of religious switching — from a continued increase to no switching at all.

“While the scenarios in this report vary in the extent of religious disaffiliation they project, they all show Christians continuing to shrink as a share of the U.S. population, even under the counterfactual assumption that all switching came to a complete stop in 2020,” according to the report. “At the same time, the unaffiliated are projected to grow under all four scenarios.”

Currently, about a third (31%) of Christians become disaffiliated before they turn 30, according to Pew Research. Some 21% of nones become Christian as young adults. Should those switching rates remain stable, Christians would make up 46% of the population by 2070, while nones would make up 41%.

If disaffiliation rates continue to grow but are capped at 50% of Christians leaving the faith, then 39% of Americans are projected to be Christian by 2070, with 48% of Americans identifying as nones. With no limit placed on the percentage of people leaving Christianity and with continued growth in disaffiliation, Christians would be 35% of the population, with nones making up a majority of Americans (52%).

If all switching came to a halt, then Christians would remain a slight majority (54%), while nones would make up 34% of Americans, according to the projection model.

Non-Christian faiths would rise to 12% to 13% of the population, largely due to migration, in each scenario. Migration does affect the percentage of Christians, becauses most immigrants coming to the U.S. are Christians, said Conrad Hackett, associate director of research and senior demographer at Pew Research Center.

“Still the greatest amount of change in the U.S.,” he said, “...currently and in the future, will come from switching.”

Researchers stressed the report contained projections based on data and mathematical models, not predictions of the future.

“Though some scenarios are more plausible than others,” they wrote, “the future is uncertain, and it is possible for the religious composition of the United States in 2070 to fall outside the ranges projected.”

One reason for the decline among Christians and the growth among the nones in the models is age. While Christians have more children than nones, they are also older. Pew estimates the average Christian in the United States is 43, which is 10 years older than the average none.

“The unaffiliated are having and raising unaffiliated children,” Stephanie Kramer, a senior researcher at Pew, wrote in an email, “while Christians are more likely to be near the end of their lives than others.”

Using mathematical models, Pew has also projected the future of religion around the world. Those models were adapted for different regions, said Hackett. Muslims, for example, he said, tend to have the youngest population and the highest fertility rates, driving the growth of that faith. However, he said, in the Gulf states, migration has brought many Christians from other countries to the region as temporary workers.

The current report takes advantage of the amount of data collected about the U.S. religious landscape. Kramer said researchers also looked at intergenerational transmission for the first time.

“The variables we used to study that were: What is the mother’s religion? And what is the teen’s religion,” she said. “If that was a match, we consider the mother’s religion transmitted.”

Researchers also looked at a relatively new trend of disaffiliation among older Americans. Sociologists have long focused on younger people, who are most likely to switch religions. But in the U.S. and other countries, older people are also starting to switch at growing rates.

“It’s not as large-scale, but it’s still significant,” said Hackett. “And it’s contributing to the religious change that we have experienced and that we expect to experience in the years ahead.”

Hackett said that the projections do not show the end of Christianity in the U.S. or of religion in general, which he expects to remain robust. And most nones, while claiming no religion, do not identify as atheists.

Kramer said the U.S. appears to be going through a pattern of secularization that has happened in other countries, though “we may be a bit behind.”

Other factors outside the model — such as changing immigration patterns and religious innovation — could lead to a revival of Christianity in the United States, according to the report. But none of the models shows a reversal of the decline of Christian affiliation, which dropped from 78% in 2007 to 63% in 2020, according to Pew research.

In the report, researchers note that “there is no data on which to model a sudden or gradual revival of Christianity (or of religion in general) in the U.S.”

“That does not mean a religious revival is impossible,” they wrote. “It means there is no demographic basis on which to project one.”

Ahead of the Trend is a collaborative effort between Religion News Service and the Association of Religion Data Archives made possible through the support of the John Templeton Foundation.