Around a decade ago, I had a conversation. The subject was something to do with church or religion more generally, and I mentioned that I’m an evangelical.

“Are you?” my conversation partner asked, surprised.

I started to explain but then paused. “I mean, of course, whether I say I’m an evangelical will depend on who I’m talking to,” I said, “and if I think they’re going to understand what I mean. Because sometimes I might say ‘evangelical’ and mean one thing and the other person is thinking something else entirely.”

These days, working for Christianity Today and with a book on evangelicalism out this fall, I can’t be that coy anymore. But if anything, I’m even more aware now of competing understandings of evangelicalism in America. The timing of that conversation is surely not coincidental: It was around the time of the first election of President Donald Trump, which helped make evangelicalism a contested part of American politics to a degree that we did not see even at the peak of the Moral Majority or the presidency of George W. Bush.

Much of the public confusion around the nature of evangelicalism stems from the way it’s handled by political pollsters. For quick surveys, often tied to elections, national polls tend to measure evangelicalism by self-ID. That is, if a respondent says she is an evangelical, so she is.

This is a defensible method: replicable and quick. And it generally produces serviceable results. But it also makes evangelicalism whatever survey participants suppose it to be, which is how we have 7 to 20 percent of American Hindus, Muslims, Buddhists, Jews, and people of no religious affiliation telling pollsters they’re evangelical Christians.

Some of this confusion is about Republican voters using evangelicalism as “a way to signal support for Donald Trump,” as Shadi Hamid (cohost of Comment’s Zealots at the Gate podcast) argued at The Washington Post in 2024. But the pattern well predates Trump—we see very similar numbers going back to at least 2012—and Hamid is mistaken to suppose that evangelicalism itself is redefined by the political signalling of low-information voters.

He contends that evangelicalism has “become about shared political convictions.” But it hasn’t. Evangelicalism is not reducible to Donald Trump.

Still, the mention of convictions sets us on the right track. For four decades there’s been a definitional heavyweight champ in scholarship on evangelicalism: the Bebbington quadrilateral, originally proposed by British historian David W. Bebbington in 1989.

These “are the four qualities that have been the special marks of evangelical religion,” Bebbington wrote: “conversionism, the belief that lives need to be changed; activism, the expression of the gospel in effort; biblicism, a particular regard for the Bible; and what may be called crucicentrism, a stress on the sacrifice of Christ on the cross. Together they form a quadrilateral of priorities that is the basis of Evangelicalism.”

This rubric of emphases was “almost immediately” adopted by other leading historians of evangelicalism, as Matthew Avery Sutton observed in his influential 2024 essay on the subject, “and it is now ubiquitous in the literature.” But Bebbington’s definition is increasingly contested by a new generation of scholars. Sutton himself is prominent among them, arguing in that same essay that the quadrilateral is “vague and generic” and “tells us nothing” about important questions of evangelical behaviour. In this challenge Sutton is joined by historians like Kristin Kobes Du Mez, Timothy Gloege, and my former Christianity Today colleague Daniel Silliman.

There’s real value in these examinations of evangelicalism from new angles, and I’ve particularly appreciated Du Mez’s proposal of an “all of the above” understanding of evangelicalism, treating belonging, behaviour, and belief as multiple facets of the same stone instead of sharply distinguishing them. We not only can but should approach this sprawling movement with insights from multiple disciplines—and often we’ll be better served if we seek to describe a centre of evangelicalism rather than define a hard boundary. (Though I think it is safe to say that evangelicals are necessarily Protestant Christians, and so, no matter what they tell pollsters, there is no such thing as an irreligious or Buddhist evangelical.)

However, for evangelicals like me and for everyone participating in American public life, it’s vital to think clearly about what that centre is. Evangelicalism is our country’s most politically significant and controversial religious bloc. Clarity and charity are not only matters of religious import but relevant to the whole of our society.

It’s Silliman’s work I want to engage here, specifically his 2021 contribution to the academic journal Church History on defining evangelicalism. It’s characteristically fascinating reading, graced with the wit and insight I always appreciated when we worked together. But I do think Silliman is significantly wrong about the quadrilateral—and wrong in revealing ways.

His argument, built around original archival research of letters and other documents from the founding of Christianity Today in the 1950s, is that “Bebbington’s definition is ahistorical, vague, and deeply unhelpful.” Instead, he contends, we should define evangelicalism as a “discourse community which is structured by its communication networks,” using a definition very like historian George Marsden’s famous quip, “An evangelical is anyone who likes Billy Graham.” The line is “quite useful,” Silliman writes, “as it directs historians to attend to actual relationships, historical affinities, and real-world conversations.”

Historians should attend to all that, of course. But Silliman’s rejection of the quadrilateral misunderstands its scope (and therefore its explanatory value), gives insufficient weight to the role of belief in evangelical life, and fails to account for the reality of social and especially media fracture in the twenty-first century as compared to the lifetime of Billy Graham.

The scope issue runs in two directions. First and less importantly, like Sutton, Silliman includes a list of things evangelicals have done, including “key moments of evangelical history,” that the quadrilateral’s four emphases (conversion, activism, Bible, cross) “cannot help the historian understand.”

But there’s no reason to suppose that the quadrilateral needs to explain it all. It’s not a theory of everything. Nor does accepting it as a basic metric exclude us from recognizing that it’s not describing the whole of evangelicals’ beliefs—we do have more than four, after all—and that evangelicals live in the world, in various contexts, and will be shaped by those contexts for both good and ill. It’s inevitable that some of what we do and think, including some very consequential things, will be best explained by something other than the quadrilateral. It would be silly to suppose otherwise.

Second and more importantly, like some other Bebbington-critical scholars, Silliman largely treats the quadrilateral as an abstract set of beliefs. This rubric is often called the “theological definition” of evangelicalism, including by its proponents, and obviously it does involve theology. Yet this categorization obscures more than it reveals.

Bebbington himself was very insistent on this matter when I interviewed him last year for my forthcoming book. The quadrilateral is sociological too, he told me, because each of the emphases cannot simply be believed in the brain. They must be lived.

This is easiest to see with activism, where faith without works is unmistakably dead. The emphasis on conversion, likewise, is not merely the mental assent of a moment but a demand for a lifetime of transformation and sanctification. Furthermore, if you have a high view of the Bible, then you have to read and follow it. And as for the emphasis on the cross, any examination of the preaching, worship, and material cultures of evangelicalism will find sociological evidence in abundance.

Not only is the quadrilateral about more than theological commitments, but it is not static. That is, expressions of these core emphases will look different in different times and places. This is evident in Silliman’s own archival research, though he does not seem to see it.

Examining correspondence among Christianity Today’s founders, Silliman finds that there “were four issues that did come up: eschatology, faith healing, atonement, and—interwoven with the other issues—the inspiration of the Bible.” He continues

Except, in fact, they were—provided we recognize that the controversies and concerns around a given Bebbington emphasis will vary from one context to another. In this case, Silliman’s eschatology, faith healing, atonement, and biblical inspiration map quite neatly onto the Bebbington quadrilateral.

The attention to the inspiration of the Bible is an easy one: That’s the quadrilateral’s biblicism. Similarly, the focus on atonement is about the cross—the quadrilateral’s crucicentrism.

Eschatology is tied to activism. The premillennial interpretation of Revelation and related biblical passages “had been quite important to fundamentalists. In many ways it defined them and explained for them their position in the world,” Silliman notes. But CT founder Nelson Bell (Billy Graham’s father-in-law) “disagreed. That was old, fight-y fundamentalism. Evangelicalism was going to be different.” It would participate in American politics and public life in a bold but attractive way, pairing an irenic tone with a firm commitment to orthodoxy, and so taking action where earlier generations of Christians withdrew because of their conviction that the world would get worse and worse until Christ’s return no matter what happened in human politics. The new evangelicals did not disavow premillennialism, but they left behind the pessimistic rejection of public activism it had encouraged.

Finally, the faith-healing debate among CT’s founders was at its root a debate about conversion. “Pentecostals prize the gift of tongues, and some have gone so far as to say that all real Christians speak in tongues,” Silliman writes (emphasis mine). The Pentecostal televangelist Oral Roberts “‘preaches the true gospel,’ Bell wrote, but the message of salvation got lost in the hubbub and spectacle.” This all falls within Bebbington’s conversionism. Such attention to who has truly been converted and the most effective way to convert people makes sense only if you believe lives need to be changed.

And that’s the thing: Evangelicals do believe lives need to be changed. Understood to include its import for belonging and behaviour and not just theology, Bebbington’s description makes that clear.

By contrast, the way Silliman talks about the correspondence between CT founders comes off as something of a just-so story. Yes, these people had friends and a network and a culture and so on—this is normal human stuff, nothing unique to evangelicalism. But what brought them together in the first place? Why this network? Why letters to these people across thousands of miles? We can profitably speak of evangelicalism as a discourse community, but why this discourse?

The answer, I think, is basically what we see in the quadrilateral. It’s about beliefs, not as abstract propositions we hold in our minds, but in that robust sense that also speaks to faithful life and practice.

That’s a way of understanding evangelicalism that has worked for many years, works now, and will continue to work—God willing—for as long as evangelicalism exists. The same cannot be said of the Marsden quip, delightful though it is, for it has already ceased to work and will never work again.

Strange as it may seem for those of us old enough to remember him as a colossus of American society, the memory of Billy Graham is fading fast. When I introduce myself to people and tell them where I work, even among Christians I sometimes get a blank stare. For a long time, my instinct was to add that CT is a magazine founded by Billy Graham. But lately I’ve given that up, for I find that at the mention of his name the blank stares do not turn to expressions of recognition.

And the problem with the quip as a durable definition goes beyond familiarity with Graham personally: Absent some enormous and unforeseeable social shift, we will not see another Billy Graham in our lifetimes. There will be no one Christian figure of comparable influence in America again.

Consider: Around the time Graham helped found CT, he filled New York’s Madison Square Garden for sixteen weeks. Hours of his preaching ran on ABC News, and The New York Times would simply print his sermons. When demand for his message exceeded what the Garden—which seats around twenty thousand people—could accommodate, Graham moved over to Yankee Stadium and packed that too.

That is almost certainly not a situation we’ll see replicated in this century, and so any understanding of evangelicalism organized around affiliation with a figure like Graham will fail to account for how much the world has changed since his heyday. How could you finish that sentence now? An evangelical is anyone who likes . . . who, exactly?

Yes, we have our celebrity pastors, bestselling authors, influencers, televangelists, and court evangelicals. But theirs are relatively small fiefdoms in a time of ever-increasing social and media fracture. The twentieth-century monoculture of which Graham was able to avail himself is no more, including within evangelicalism.

All this matters for all of us because of the sheer number of evangelicals in America and our unique place in politics and public life.

Already faith in the public square is often treated as strange and inherently suspect. It will be deeply deleterious for our country if an increasingly irreligious society comes to believe evangelicalism is reducible to being a white Republican who shops at Hobby Lobby and likes, well, not Billy Graham, but perhaps some less appealing figure whom most evangelicals do not like. That kind of misunderstanding will have—is having—far-reaching negative consequences for our polity.

And such a misunderstanding is deleterious for those of us who are evangelicals, especially insofar as it inclines us to be ashamed of our own tradition. Evangelicalism has its flaws and failings, as any movement on this scale inevitably will. But it needn’t be perfect to be good, and it is good. (On this, I know from past conversation, Silliman and I agree, however we differ on definitions.)

Evangelicalism is busy, as Matthew Milliner wrote for Comment in November, with “unflashy faithfulness.” It may deserve reform, but not diminishment or scorn. The Bebbington quadrilateral can’t explain everything about evangelicals, but conversion, activism, the Bible, and the cross—yeah, that’s what we’re about.