In a recent review ofChristena Cleveland’sDisunity in Christ:Uncovering the Hidden Forces that Keep Us Apart,Paul Louis Metzger wonders, “What leads people to associate with those who are similar, while distancing themselves from diverse others? What causes us to categorize other groups in distorted ways?”

I remember reading H. Richard Niebuhr’sThe Social Sources of Denominationalism early in my seminary career, and Niebuhr’s analysis made a very strong impression on my admittedly impressionable sensibilities. It was clear to me then, and still is now, that much of what constitutes disunity in the Christian church is imported from the broader culture and has nothing to do with a people in which there is “neither Greek nor Jew.” These concerns for principled ecumenical unity are in large part what animated my later book Ecumenical Babel.

And yet in denouncing the tribalism that is an endemic temptation for all forms of fallen munity, we must be careful not to embrace a simplistic, milquetoast version of Christianity that papers over our real differences, and our uniqueness as individual persons created in the image of God, each one of us with our own perspectives, callings, hopes, fears, and trials.

We need to embrace an understanding of diversity without falling into disunity, a diversity within unity that mirrors in our own creaturely way the call to unity expressed in Jesus’ high priestly prayer.

One step in plishing this might be to recognize that diversity and difference as such is not simply a feature of the fallen world. In fact, as Lord Acton has observed, using a synonym for diversity, that is, inequality is “the basis of society.” Now as Acton continued, he did have in view the dangers attending to a fallen state of nature: bined and put things mon to protect the weak against the strong.” But as Abraham Kuyper would later put it, this diversity or inequality predates the fall: “the mere fact that God created a man and a woman proves indisputably that identical uniformity was not part of the plan of creation. So we may draw no other conclusion than that the rich variety among people, in terms of aptitude and talent, came forth from the creation itself and belongs to the essence of human nature.”

Likewise Herman Bavinck, Kuyper’s younger contemporary, argues:

By creating humanity as male and female God equipped them to fill the earth and subdue it. This duality of sex, this institution of marriage, contains in nuce all subsequent social relationships: husband and wife, parents and children, brothers and sisters, servants and freemen, civil rulers and subjects. It is here also that we see, in principle, all the inequalities that would e to pass among people: differences in body and soul, in character and temperament, in gifts of understanding and will, in heart and hand, and so forth. Inequality is a given of creation, grounded in the very will of God himself, and not first of all a consequence of sin.

This created social diversity is distorted, exaggerated, and broken in the fall, but does not arrive on the scene as something novel as such. Hints of the eschatological diversity of the consummated kingdom can be found throughout the New Testament, from Pentecost to the New Jerusalem.

A significant challenge for the church is wisely discerning what true and principled diversity might look like. After all, much of Western society today is saturated in a culture that celebrates, if not idolizes, a particular conception of diversity. As Metzger puts it, we need to “distinguish more clearly between areas where theological reconciliation is possible and areas where it is not.”

This need for discernment is one of the reasons that I selected for the dedicatory formula inEcumenical Babel a variation of the familiar Latin quotation:In necessariis unitas, in dubiis libertas, in omnibus caritas(unity in necessary things; liberty in doubtful things; charity in all things). In my book, I took a variant that can be found in the seventeenth century, and which renders the final line: in omnibus prudentia et caritas. We need a prudent, wise love that, in Metzger’s words, “insists on certain rightful boundaries between truth and falsehood.”

In these ways, a true conception of diversity es the basis of a true society, in the deepest and most principled senses. And therefore a perennial challenge facing human society is to determine which diversities are valid or permissible and which are not. As I conclude in a recent paper exploring the moral challenges of diversity and inequality in economic terms, “We need to be able to judge prudently when, if ever, indignation at the wealth of some is righteously justified, who gets to make such judgments, as well as when we should suppress our disposition to grieve the prosperity of others and instead rejoice with them.”