In his review of Hunter Baker’s latest book, The System Has a Soul, Doug Wilson picks up on the allusion in the title. And in his introduction to For The Life of the World, Stephen Grabill makes explicit use of this metaphor for the relationship between Christians and society as found in the patristic Letter to Diognetus:
To put it simply: What the soul is in the body, that Christians are in the world. The soul is dispersed through all the members of the body, and Christians are scattered through all the cities of the world. The soul dwells in the body, but does not belong to the body, and Christians dwell in the world, but do not belong to the world.
At the time of this letter, in the second century A.D., the contrast of this vision with dominant paradigms would have been sharp. Varieties of philosophical and religious reflection derived from Plato affirmed a “world soul” that animated the cosmos. Later Neoplatonism, including the doctrine of the world soul, would subsequently be taken up more or less critically by a number of Christian thinkers, but the juxtaposition between such views and the affirmation of human beings, specifically adherents of the Christian religion, as the “soul” of the world could hardly have been mistaken in the times of the early church.
The context of the Letter to Diognetus is echoed in the work of another patristic figure, Tertullian of Carthage, who in his apologetic wrote of Christians:
We sojourn with you in the world, abjuring neither forum, nor shambles, nor bath, nor booth, nor workshop, nor inn, nor weekly market, nor any other places of commerce. We sail with you, and fight with you, and till the ground with you; and in like manner we unite with you in your traffickings — even in the various arts we make public property of our works for your benefit.
On this account, Christians are present throughout society, extended to each member no matter how removed, just as the soul animates the entire body.
This image of Christians as the soul of the world — as an animating presence — spread throughout society, corresponds in many ways with the biblical images of salt and light, found particularly in the Gospel accounts of the Sermon on the Mount. Thus Jesus tells his followers, for instance:
You are the light of the world. A town built on a hill cannot be hidden. Neither do people light a lamp and put it under a bowl. Instead they put it on its stand, and it gives light to everyone in the house. In the same way, let your light shine before others, that they may see your good deeds and glorify your Father in Heaven (Matt. 5:14-16 NIV).
The Dutch Reformed theologian Herman Bavinck picks up this imagery in his distinction between the Gospel as a pearl and a leaven. In the former sense, the Gospel is a treasure of incalculable value, echoing the usage in Jesus’ parable of the pearl of great price. In the sense of leaven, however, the Gospel and its confessors act as agents of renewal and transformation within the larger social order. Thus, writes Bavinck:
Although the worth of Christianity is certainly not only, not exclusively, and not even in the first place determined by its influence on civilization, it nevertheless is undeniable that Christianity indeed exerts such influence. The Kingdom of Heaven is not only a pearl; it is a leaven, as well. Whoever seeks it is offered all kinds of other things. Godliness has a promise for the future, yet also for life today. In keeping God’s commandments, there is great reward. In its long and rich history, Christianity has borne much valuable fruit for all of society in all its relationships, in spite of the unfaithfulness of its confessors.
This distinction between the Kingdom of Heaven as pearl and leaven corresponds with a distinction made by Bavinck’s contemporary and erstwhile colleague, Abraham Kuyper. Kuyper distinguishes between the church conceived as an “institute” and an “organism.” The church as an institution corresponds to the work of the church as we often think of it: its official programs, corporate worship, sacraments, and preaching. The organic church is a way of thinking about Christians that sees them as spread out throughout life, as a kind of leavening agent, in the world and through their individual callings.
The pluralism of our contemporary world has some strong resonances with the times of the early church. But the hegemony of scientific materialism today makes the challenge one primarily, not of determining what the soul of the world consists of, but whether there is such a reality as a soul or not. To this dominant challenge of modern secular discourse Baker speaks a salient and ancient truth worth recalling: “The church is the soul of the system.”