When a couple marry in a church, synagogue or mosque, the ceremony does more than sanctify a union. Often, it binds two families to an institution.

For centuries, marriage and child-rearing have been among the main ways adults are integrated into congregational life. Couples who share the same faith tend to be more observant, and they often raise children within that tradition – bringing the next generation into congregational life. More marriages mean more families in pews and more children raised in the faith.

That helps explain why the rise of single adults is so unsettling for many faith communities today. In the United States, 42% of adults were not married or living with a partner in 2023, up from 38% in 2000. This shift is unlikely to change soon: A quarter of 40-year-olds have never been married, and a third of Gen Z are projected to never marry.

At the same time, the share of unmarried Americans who belong to a religious congregation has fallen well below that of married Americans. According to the Pew Research Center’s 2023–24 Religious Landscape Study, 68% of married adults identify as Christian, compared with about 51% of never-married adults. Twenty-four percent of married Americans are religiously unaffiliated, compared with 39% of Americans who never married.

As a behavioral economist and a business school professor, I study what I call the “solo economy”: how the rise of single adults is reshaping workplaces, taxes and consumer markets. Religious institutions are the latest domain to face the same shift. They are not simply confronting lower marriage rates. Many of them, I contend, are reckoning with the consequences of treating unmarried adults as incomplete members of the community.

According to the Survey Center on American Life, the gap in religious membership between married and unmarried Americans has widened substantially since the 1990s.

At the time, 71% of married Americans said they belonged to a religious congregation, compared with 64% of unmarried Americans. In 2019, those numbers were 59% and 45%, respectively. Barna Group, an........

© The Conversation