Editor’s Note: Diana Butler Bass (@DianaButlerBass) is the author of 11 books on American religion and cultural trends, including her most recent, “Freeing Jesus: Rediscovering Jesus as Friend, Teacher, Savior, Lord, Way and Presence.” She was a member of the Public Religion Research Institute board from 2008 to 2018. The views expressed here are hers. Read more opinion on CNN.

CNN  — 

In 1994, I quit.

Twenty years earlier, I’d been born again. I had grown up in a liberal Methodist church but started going to a nondenominational church with high school friends. When I told my friends that I’d given my life to Jesus, there were hugs and tears. Jesus embraced me, and so did they. I had a new family – and everything changed.

Diana Butler Bass

I had not only converted to Jesus, but I’d entered another world, one with its own language, practices, ethics and expectations. I learned this sort of Christianity had a name: “Evangelical” meaning “good news.” And it seemed very good to me. Evangelical faith was warm, assuring, enthusiastic, serious and deeply pious. I attended an evangelical college, graduated from an evangelical seminary and did doctoral work with a leading evangelical scholar. I was proud to be evangelical.

Evangelical Christianity was everything to me back then: faith, work, friends, life. It stayed that way until my questions started. Evangelicalism became the religious right, it became obvious that women would never be accepted as leaders, and closeted gay evangelical friends died of AIDS.

After a protracted internal struggle, I couldn’t do it anymore. I joined a liberal Episcopal church, returning to the kind of mainline Protestantism I’d known before being born again.

It was hard leaving evangelical Christianity. Through the years, I’d occasionally meet someone who had a similar experience, but such encounters were often random, or felt furtive. Mostly, when it came to my spiritual journey, I’ve felt alone.

Until this week.

On July 8, the Public Religion Research Institute (PRRI) released its American Religious Landscape survey for 2020. The report resembled those of recent years, affirming now-familiar trends shaping 21st century American religion: increasing racial diversity in Christian communities, the sizable presence of world religions other than Christianity and the explosive growth of those who are religiously unaffiliated.

In other words, there were no major surprises – except one. Unlike previous surveys, this one showed that the decline among White Christians has slowed. Indeed, the percentage of White Christians actually rose slightly due to growth in an unlikely category – an increase among white mainline Protestants, “an uptick” of 3.5% in their proportion of the American population.

This uptick is especially surprising when compared to the drop in White evangelical Protestantism. The report pointedly states: “Since 2006, white evangelical Protestants have experienced the most precipitous drop in affiliation, shrinking from 23% of Americans in 2006 to 14% in 2020.”

White mainline Protestantism is growing; White evangelicalism is declining. And that is big news.

Most researchers divide White American Protestantism into two large families: Evangelical and mainline. Evangelicalism comprises a multitude of theologically conservative Protestants who typically belong to groups such as the Southern Baptist Convention, the Assemblies of God or to independent, nondenominational mega-church congregations.

Mainline Protestantism (sometimes referred to as “old-line,” “mainstream,” or “ecumenical”) is an umbrella designation for those more theologically moderate and liberal Protestants who identify with the Episcopal Church (TEC), Presbyterian Church, USA (PCUSA), United Methodist Church (UMC), United Church of Christ (UCC) or the Evangelical Lutheran Church in America (ELCA).

Chances are that if you grew up Protestant and attending church in America, you worshipped on one side of this divide or the other, even if you did not know this history or which camp your church was in. Or, like me, you moved between them, as I was first mainline, then evangelical, and then mainline again.

PRRI indicates that the mainline rebound is significant: “The slight increase in white Christians between 2018 and 2020 was driven primarily by an uptick in the proportion of white mainline (non-evangelical) Protestants… Since 2007, white mainline (non-evangelical) Protestants have declined from 19% of the population to a low of 13% in 2016, but the last three years have seen small but steady increases, up to 16% in 2020.”

For several years, observers have noted the decline of White evangelicalism. As white evangelical numbers declined, the percentage of religiously unaffiliated Americans went up. There appeared to be a correlation between the two – ex-evangelicals moved to the “none” category. Over the last three years, however, the unaffiliated category has stabilized while the white evangelical exodus continued. At the same time, the white mainline category has risen.

This shift suggests that some portion of ex-evangelicals are finding their way toward mainline or another non-evangelical Protestant sense of identity.

This doesn’t mean that Americans are necessarily returning to mainline churches in droves. The PRRI study is not about church attendance or membership. It isn’t about what people do. It is about identity - labels people use to describe their religious lives. The data suggests that White Protestants are distancing themselves from “evangelical.” Many apparently leave religion altogether. But others – whose numbers might be that modest “uptick” – may be reacquainting themselves with mainline Protestantism.

Dividing Protestants into two categories goes back to the early 20th century when the two groups were called “fundamentalists” and “modernists.” In the 1920s, Protestants quarreled over the Bible and evolution, their churches and seminaries split. The two factions largely went their separate ways, eventually morphing into “evangelicals” and “mainliners” as they are called today.

In the middle decades of the 20th century, mainline Protestants held more cultural and political power. By the mid-1970s, however, their numbers – and influence – began a rapid decline.

As the mainline went into a demographic tailspin, evangelicals fought for greater recognition in politics and culture, surprising nearly everyone with the size of their churches, the energy of their organizations and a kind of expressive spirituality. Their robust ascent into the public conversation, their political acumen and their fundraising prowess, transformed American politics and church life seemingly overnight.

In the last quarter of the 20th century, mainline Protestantism faded from public view. “Evangelical” became coterminous with “Protestant.” If one was born after 1980, it was hard to know that mainline Protestantism even existed.

Pendulums do, however, swing. And it could be that this is the historical moment when America’s Protestant pendulum is moving away from its evangelical side to its more liberal one once again.

What is certain is that America is no longer as evangelical as it was. But it is not as mainline as it was in the mid-20th century either. Both terms used to describe American Protestantism are more fluid than most people know, and both “evangelical” and “mainline” are undergoing changes. This may lead to a genuine renewal of the old mainline Protestant denominations – it is too early to tell. This shift, however, will have political and social consequences.

Get our free weekly newsletter

  • Sign up for CNN Opinion’s newsletter.
  • Join us on Twitter and Facebook

    Ultimately, data is about stories. This recent PRRI poll suggests a new one may be unfolding.

    Beyond scholarly speculation, analytical research and historical theories, however, numbers also quantify the experiences of real people. There are millions of stories – enough to now show up as data – of spiritual journeys of those who have left evangelicalism and are searching for a new sense of identity, deeper meaning and a place to call home.

    Stories like mine.