While the portion of Americans who hold to evangelical beliefs about God and the Bible continues to fall significantly, those under age 40 who fall into the category of atheist, agnostic or “nothing in particular” are quickly approaching 50%.

Those data are from the first of a five-part study released this week from Probe Ministries’ Religious Views & Practices Survey, which comprehensively analyzed data collected in the last decade by Barna, Pew Research, GSS (General Social Survey) and Probe. The Dallas-based organization will release each of the other four parts monthly through November.

“America is changing before our very eyes,” Kirby Anderson, president of Probe and a visiting professor at Dallas Theological Seminary, said in a news release announcing the findings. “We can no longer assume that our fellow Americans see the events in our society from a Biblical worldview.”

Of particular concern in the survey are the beliefs of younger Americans (under age 40), which have sharply drifted from previous generations at an alarming rate.

• Among a group deemed Emerging Adults (ages 18-29), the “Unaffiliated” population nearly tripled between 1988 and 2018, from 13% to 35%.

• The portion of Emerging Adults who claim affiliation with evangelicalism is down from 28% in 2007 to 20% in 2019, and the percentage of that age group who would hold to what the survey terms a “Basic Biblical Worldview” is only 5%.

According to the survey, a Basic Biblical Worldview would hold that “God is the all-powerful, all knowing, perfect creator of the university who rules the world today”; would “strongly agree” that “the Bible is totally accurate in all of its teachings”; and would “disagree strongly” that salvation can be earned if one’s good outweighs the bad, and with the notion that Jesus sinned while living on earth.

Also alarming, Anderson said, are data suggesting that as young people who grew up attending church mature into their 30s, marry and raise children, a growing number of them are not returning to church as many thought they would. In fact, a rising percentage of 30-somethings are joining the ranks of the Unaffiliated.

“Pastors and church leaders need to understand what this means for their churches and Christian organizations,” Anderson said. “We can’t even assume that many members of our churches even view the world Biblically.”

The drop in belief is even more severe among younger non-evangelical Protestants and Roman Catholics. Those described as young adult “Other Protestants” made up around 25% of their age group in 1988; today they are about 12.5%.

Also noteworthy, according to the survey: Among Americans 55 and younger, only about one-third believe in “an active creator God.”

The second of four reports will be released by Probe in August.

“In the meantime,” Probe Ministries urged, “be in prayer about what you can do in your sphere of influence to stem the trends listed above.”