Pluralism is often perceived as a threat to faith, associated with relativism and a loss of religious substance. I take a contrary position. It seems to me that pluralism is good for faith. For several years now, my work as a sociologist has circled around the phenomenon of pluralism. The result of this preoccupation is a book I published in 2014, The Many Altars of Modernity. It is an exercise in sociological analysis of the contemporary religious situation, necessarily free of theological presuppositions; I could have written this book if I were a Muslim, or a Buddhist, or an atheist. In other words, I wrote wearing the surgical mask of social-scientific objectivity. Behind this mask, however, I am a Christian, specifically with a (not very orthodox) Lutheran flavor. Now I want to take off the surgical mask and reflect theologically upon what I see as a sociologist.

When I started my career as a sociologist of religion (this was around the year of Lincoln’s Second Inaugural), like just about everyone in the field, I operated within so-called secularization theory. We thought that modernity invariably means a decline of religion. It took me more than twenty years to conclude that the theory is empirically untenable. This had nothing whatever to do with my changing my own religious beliefs; it had everything to do with how I came to read the evidence, which is overwhelming. The world today is as religious as it ever was, in places more so than ever. (There are ­exceptions, notably Western Europe and an international so-called intelligentsia. These have to be, and can be, explained.)

Secularization theory was not completely false; it was a massive exaggeration of what was a correct insight. It is beyond dispute that secular discourse, probably originating in modern science and technology, has transformed human life. (One such transformation: In premodern societies, almost half of all children died before age five; today most children, even in poor countries, live to adulthood.) The distinguished Canadian philosopher Charles Taylor wrote a big book with the title A Secular Age (2007). He gives a rich description of what he calls the “secular frame,” a view of the world without religious transcendence. But he exaggerates the degree to which this discourse has pushed religion to the margins. We don’t live in a secular age; we live in a pluralist age.

This pluralist age has important implications for religion, but they are different from those of secularity. We can speak of two pluralisms. The first concerns the fact that many religions and worldviews coexist in the same society. This is not unique to the modern era. The second kind of pluralism involves the coexistence of the secular discourse with all of these religious discourses. This pluralism, which is uniquely modern, has tended to accentuate the first kind, the pluralism of religions and worldviews. When I’m sick and my doctor is Jewish or Hindu, our shared secular vocabulary gives us a commonality that makes our religious differences something almost scandalous. How is it that we can agree on medical and other scientific or technical questions, yet not on ultimate matters?

There are some people who avoid the scandal of pluralism because they operate exclusively within a secular or a religious discourse (say, atheist Swedish sociologists, or Russian monks who practice the perpetual Jesus Prayer). However, most people of faith today manage to operate within both discourses. The question is not whether this can be done; we know that millions of people do it. The interesting question is how they do it. The category of “relevance structure,” as it was developed in the sociological theory of consciousness by Alfred Schutz (1899–1959), is very helpful in developing an answer to this question. I would love to expound this over the next fifty pages; but, alas, this would exceed what is needed at this juncture (and would tax the patience of the editors, who so often underestimate the stamina of genuinely interested readers).

Instead I will clarify just what is meant by religious pluralism as distinct from other forms, such as ethnic, racial, and linguistic diversity. The term “pluralism,” as far as I know, was coined by Horace Kallen (1882–1974), an American philosopher who not only described but also celebrated the diversity of this ­society. The suffix “-ism” suggests an ideology rather than a simple fact, but I’m using the term in the descriptive sense. (For a while, in the service of precision, I used the term “plurality.” People then asked me, “you mean—like pluralism?” and so I decided to give up terminological precision in favor of vernacular intelligibility.)

Pluralism thus means the coexistence, generally peaceful, of different religions, worldviews, and value systems within the same society. This has occurred before in history, for example, along the Silk Road that linked Europe and China, in the better years of the convivencia of Muslims, Jews, and Christians under the caliphate of Cordoba, and at the court of the Moghul Emperor Akbar. The British colonies in North America, from which came the United States, were pluralistic from the beginning out of practical necessity, even before Thomas Jefferson and others made an ideology of religious freedom out of it. A particularly significant case of premodern pluralism is that of the late Roman Empire, especially in its big cities. The report of the Apostle Paul’s visit to Athens (Acts 17) provides a vivid picture of the pluralism that facilitated the growth of an obscure Jewish sect into a universal religion.

What is distinctive today is that this pluralism (not always protected by religious freedom) has become globalized. It is estimated that there are now about 100 million Christians in China (more than the number of members of the Communist party), and at least sixteen million Muslims in the European Union (tens of thousands more as I’m writing). Protestant businessmen from South Korea smuggle Bibles into China and Central Asia. Hare Krishnas dance and chant in American shopping malls.

Many Christians are enthusiastic about the global growth of Christianity over the last century. But they tend to deplore the situation of increased pluralism in once uniformly Christian societies. They like the idea of house churches in China, but they regret the construction of mosques in the Netherlands. This ­reaction is misguided. It fails to recognize the religious benefits of pluralism.

First benefit: It becomes more difficult to take a religious tradition for granted. Acts of decision become necessary. We’re social animals, and so if everyone around me agrees on something, I will very likely share this agreement (unless I am a very unusual person—say, like Socrates). Pluralism makes this sort of consensus very rare. It means we can’t escape the fact that there are other people who hold onto other truths and live by other values. Their simple presence, and the fact that they do not seem to be crazy, adds an element of uncertainty to my worldview.

Of course, it helps if I can convince myself that they are crazy, and that I’m the only one who is not. In one form or another, this has been a common approach throughout history. But our shared modern secular discourse short-circuits that strategy. It’s hard to write off my Confucian lab partner as crazy when he’s so good at science. If I begin to have extensive conversations with those who have different religious convictions, the uncertainty deepens.

This does not usually mean that I give up my ­previous beliefs and go over to theirs. But my faith is now tinged with a penumbra of doubt. My first reaction may be to avoid the dissonance. That is the project of fundamentalism, which can be simply defined as an attempt to restore or replace the taken-for-granted-ness that has been lost. But I have other options. I can stay, possibly with some reservations, within the tradition in which I was raised. I might join another faith community (especially if such a decision is protected by legally instituted religious freedom). Or I can put together bits and pieces from several traditions, as one may put together Lego ­pieces to build one’s own little worldview.

This state of affairs—the loss of certainty—is of course disturbing. But it is a good thing if one values deliberate and reflective assent as a component of authentic faith. I think it is better for social conditions to encourage us to decide upon faith than for us to live amid circumstances that “give” us faith, making our religious identity akin to our hair color or our particular allergies rather than a fully personal quality that arises from our free assent.

Preachers often counterpose faith (good) and ­unbelief (bad, the sin of turning against God). This is true as far as it goes, but it is also misleading. Another opposite of faith is knowledge. I know that I am sitting in my study overlooking the skyline of Boston, not in Hamburg, where I gave a version of this essay as a lecture recently. Gnosticism was an important early rival of Christianity. Gnosis in Greek means “knowledge”; the Gnostic teachings initiated individuals into a secret knowledge that supposedly conveyed truth. Christian faith is not a form of esoteric gnosis. Rather, in the words of the Letter to the Hebrews (11:1), “faith is the assurance of things hoped for, the conviction of things not seen.” Whoever was the author of this early New Testament text, he evidently recognized that faith coexists with the recognition that reasonable people may quite reasonably think otherwise, and that recognition involves an existential awareness of the contingency of one’s faith. Many years later, Luther confessed: “I don’t ­really know what I believe; I know in whom I believe.” Elsewhere he defined faith as trust. We can see how pluralism deepens this trust, for it knocks away false assurances provided by a uniform social consensus.

Second benefit: Freedom is a great gift, and pluralism opens up new areas of freedom. Pluralism plunges individuals toward free decisions, a good in itself. The Declaration on Religious Freedom of the Second Vatican Council, Dignitatis Humanae, defined it very well: Religious freedom is a fundamental right rooted in human dignity. It entails not just the right of Catholics to proclaim their truth, but of all persons to follow their faith or to have no faith. Dignity, faith, and freedom are profoundly linked. The exercise of freedom is not always easy. The Spanish writer Miguel de Unamuno (1864–1936), in his famous book The Tragic Sense of Life, presents the figure of Don ­Quixote as an icon of freedom. He concludes the book with the words “May God give you not peace, but glory.” Religious homogeneity certainly makes faith easier, and in that sense we can go through life peacefully, untroubled by the religious convictions we’ve adopted by osmosis. Better, though, the ­glorious free decision to cast our lots with religious truths that pluralism makes questionable.

Third benefit: If pluralism is combined with religious freedom, all religious institutions become in fact voluntary associations (whether religious believers find this theologically congenial or not). This changes the relation between clergy and laypeople, the relation between churches, and between them and the state. The laity gains power, even in hierarchical churches, and that makes for vitality. Different churches, deprived of coercive power as state-sponsored religious monopolies, become peaceful competitors; this creates a sort of religious market (though one should not exaggerate the applicability of concepts derived from economics). And the state, religiously neutral even if it is still symbolically linked with a specific tradition, can serve as an impartial arbitrator. This typically entails some version of the separation of religion and the state (whether de jure, as in France or the U.S., or de facto, as in England). The law operates within a secular discourse, even if a judge is personally religious. This means that citizens can have different reasons for affirming a moral principle. For example, Christians may support legislation on human rights because all human beings are created in the image of God, but non-theists may support the legislation using a very different discourse. This strengthens democratic culture and encourages different religious communities to become full participants in public life.

Fourth benefit: Pluralism influences individual believers and religious communities to distinguish between the core of their faith and less central elements. Inevitably, the interaction with those who have different religious convictions, especially in circumstances where we share a common secular discourse, relativizes my faith. I call this process “cognitive contamination.” It leads me to enter into a kind of bargaining process. I may give up some elements of my faith that are not essential, while the core remains nonnegotiable.

Rabbi Hillel the Elder, one of the fathers of rabbinical law in the first century bc, was once asked (mockingly, I think) whether he could explain the meaning of Torah while standing on one foot. He said yes, then pronounced what was probably the first formulation of the Golden Rule: in his version, “Do not do to others what you hate if it is done to you.” With all due respect, Hillel should have used a different sentence, since the Golden Rule pertains to human relations rather than to the more fundamental relation to God, namely the Shema, the basic Jewish confession of faith: “Hear, O Israel, the Lord is our God, the Lord is One.” In any case, after Hillel got back on both feet, he said something wonderful: “The rest is commentary.” And of course rabbinical law is a centuries-long debate about the meaning of Torah. But the Shema remains central, the ­nonnegotiable.

One would have no difficulty standing on one foot while explaining the meaning of Islam—the ­Shahada: “There is no god but God, and Muhammad is his messenger.” Things become more complicated if one moves east from the monotheisms of western Asia, but I could suggest a similar procedure to explain Hinduism and Buddhism (though not here, not here!). Is there a comparable standing-on-one-foot explanation of the meaning of the Gospel? I think yes: “Christ is risen.” Then, of course, there are many questions—Hillel’s “commentary.” Who is Christ? Was the tomb empty? Was the body of the risen Christ a revived corpse or (as the New Testament suggests) a very different sort of body? What is the meaning of Christ’s Resurrection for human hope beyond death? For all of creation? But this Easter proclamation is the core of the Gospel. In the words of the Apostle Paul, “If Christ is not risen, our preaching is in vain, as your faith is in vain” (l Cor.15:14).

But what about all the other miracles recounted in the New Testament? Did Jesus walk on the water of the Sea of Galilee? If he was what I believe he was, I would not exclude the possibility. But my faith would certainly not be in vain if it turned out that he didn’t. Once more, pluralism forces me to discern what’s really at stake in my faith, freeing me from a false emphasis on what’s less decisive.

I started out with sociology. Let me end with theology in the form of a story from the unlamented history of the Soviet Union. From time to time, the Communist party conducted campaigns to propagate “scientific atheism.” On one such occasion, all the inhabitants of a village, including the local Orthodox priest, had to assemble in front of the church to listen to an hour-long lecture about the illusions of religion. Then the commissar made a generous gesture and said that the priest had five minutes for a rebuttal. The priest came forward and said, “I don’t need five minutes.” He then turned to the assembled villagers and said, “Christ is risen!” They replied with the proper liturgical formula: “He is risen indeed!” The priest then returned to his place in the congregation. We should appreciate the way in which pluralism can bring us to what really and finally matters most for our faith.

Peter L. Berger is emeritus professor of sociology at Boston University.