Despite a growing distrust of religious institutions and dramatic changes in American family life in recent decades, Americans’ belief in a higher power is robust.

The lowest number of U.S. adults in 78 years of a Gallup survey reported believing in God, mirroring the steady erosion in American religious engagement in recent decades. Yet with 81 percent professing belief, the number still represents a robust majority of Americans. The data show that conceptions of God vary dramatically between individuals, but a general belief is widespread. 

“We’re seeing a lot less belief in the traditional Judeo-Christian God and a lot more belief in a divine higher power,” a political and religious behavior researcher, Ryan Burge, said. 

The survey showed that 70 percent of individuals born between 1925 and 1945, known as “the Silent Generation,” identified as Protestant or Catholic. This number drops to 37 percent of those born between 1997 and 2012, Generation Z. 

In the trajectory of a generation’s growing disillusionment with religion, Mr. Burge explained that religious behavior, defined as regularly attending religious services, is the first quality to subside. “The second thing that goes away is your affiliation with a religious tradition — instead of saying you’re Catholic or Protestant or Jewish or Muslim, you’ll say that you’re non-religious or atheist/agnostic,” he said. “The last thing to go away is belief.”

These trends among Gen Z and millennials, individuals born between 1981 and 1996, partly result from an erosion of confidence in religious leaders and organized practice, which have been aggravated by disclosures of sexual abuse by Catholic priests in recent years and what many criticized as the insufficient response of churches to the #MeToo movement.

“There’s no question that millennials feel less comfortable with the religious institutions that their parents and grandparents participated in,” an authority on American religious history, Ann Braude, said. 

Dramatic changes in American family life further explain the divorce of religious beliefs from institutional authority. “If you are raised in a religious family, you are attached to a religious community, you make friends through your church and related religious activities, you are far more likely to remain religious than if you didn’t have those experiences,” a polling and public opinion expert at the center-right think tank, the American Enterprise Institute, Daniel Cox, explained. 

An increasing number of moderate and liberal families are opting out of raising their children in a religious household, often reasoning that particular religious teachings are at odds with their own values. “Young adults are starting from a much lower religious baseline in terms of how they were raised,” Mr. Cox said.

The proliferation of interfaith unions, marriages between those who have no religion, as well as single-parent families that may face financial and time constraints contribute to the demise of traditional religion. Mr. Cox added that “a lot of denominations and congregations have done very poorly to adapt to changing family experiences and priorities.”  

For young adults today, defined as 18- to 29-year-olds, identity formation relies more on personal aptitude than religious devotion. “The focus has become less on establishing and building community and more about individual achievement and enrichment activities,” such as participation in sports, arts, music, and other extracurricular experiences, Mr. Cox said. 

Augmenting this trend, middle-class parents have evinced increasing pressure to expand their childrens’ skillsets so they can attend competitive colleges and have successful careers.

Amid this turn from the communal and institutional to the personal, “concerns about spirituality and transcendence are very much alive among millennials,” Ms. Braude said. “The questions that religious institutions formerly provided answers to” remain common. 

Although Gallup reported that young adults show the lowest rates of belief out of any age group, still 68 percent of them maintain a belief in God, and 30 percent say God hears prayers and can intervene.

Ms. Braude urges “people in higher education and particularly in liberal institutions to take the positive side of these statistics very seriously,” noting that Americans’ belief in God has decreased only minimally since the Gallup survey started in 1953.

Yet the polarization of religion has deprived many young adults of more moderate religious institutions to fulfill their concerns for greater meaning and purpose. Even as Americans have become more secular, many have become more devoutly religious, with fewer people identifying in between these two poles. 

“Just as we’re seeing the death of the Independent or the moderate Republican or the moderate Democrat, we’re seeing the death of the moderate religious person in America,” Mr. Burge expressed.

Mainline Protestant Christian churches, which include Methodists, Episcopalians, Baptists, Presbyterians, and other denominations, better align with the priorities of younger, liberal adults and religious moderates, as they increasingly support female pastors, LGBTQ rights, and social justice issues.

Yet as the proponents of these causes are increasingly less religious, the membership in more progressive churches has dwindled. Meanwhile, membership in evangelical churches has swelled because of the strictly conservative religious guidelines, Mr. Burge argued. Social media has helped raise interest in these more extreme practices by amplifying fringe religious views and silencing more moderate ones.

“No one is getting the message that there are still religious groups in America today that are religious but also affirming,” Mr. Burge said. “A lot of young people think you can’t be Christian and be pro-LGBTQ because there are no places for you, when in reality, there are.”

Mr. Burge speculates there might eventually be a movement of young, secular Americans toward traditional, communal outlets for their spiritual inclinations. “It used to be that you were raised religious, and then you rebelled against that by becoming non-religious,” he said. “But imagine you were raised in an atheist household, and then the most countercultural thing you can do is become religious as an adult.”

“For every movement, there’s a countermovement in American culture,” Mr. Burge said.