When theologians try to make a connection between the doctrine of the Trinity and the doctrine of the church, they take three main approaches: communion, mission, or structural analogy.
- Communion: This approach emphasizes the overlap between two vocabularies of communion: inner-trinitarian perichoresis on the one hand, and churchly koinonia or fellowship on the other. Both can be called communion. This approach to linking church and Trinity works best for those who locate the churchiness of the church in being centered on the eucharist. It commends itself to thinkers who strongly desire to see the underlying unity that holds together different churches; it’s a “church of churches” approach that draws wider circles taking in all the communions into the greater communion of the triune God. What have been called communio ecclesiologies grew out of mid-century ecumenical discussions, and were especially developed among Roman Catholics after Vatican II. Motto: “That they may be one, as we are one.”
- The mission approach connects the Father’s sending of the Son and Spirit with the church’s sending to the world; it locates the church’s being in the work of mission or sent-out-ness. This way of linking Trinity and church thrives in the context of what have been called missio Dei ecclesiologies, which grew out of world missionary discussions in the mid twentieth century. Motto: “As the Father sent me, so I send you; receive the Holy Spirit.”
- The structural analogy links a triadic structure in the Trinity to a triadic structure in the church. It identifies patterns of correspondence between the immanent order of the trinitarian persons and the ordered polity of church leadership. Theologians whoa argue this way are usually preoccupied with the question of where to locate authority among the three, even if their particular point is to make sure authority is shared out evenly. This approach rarely stands on its own; it tends to be used to draw attention to the Trinity, but then turns out to accompany or illustrate one of the first two approaches. Motto: “Hey look, threes!”
There may be a fourth approach worth considering as well. Often when asked to link Trinity and church, theologians will offer a series of biblical passages or images that, taken together, describe the church in a way that relates it to the three persons of the Trinity. For instance, “people of God, body of Christ, temple of the Spirit.” But again, it seems to me that this way of organizing the material tends to be a way of alternating between communion and mission, depending on the interpretation you go on to give each passage: “people of God” is likely missional; “body of Christ” likely communion-focused, and so on.
Finally, I think any attempt to link the doctrines of Trinity and ecclesiology needs to be governed by the absolute priority of the doctrine of God. It needs to follow a path from the perfection of God’s being down through the ordered series of God’s freely chosen actions in salvation, which take trinitarian form as the Father, Son, and Holy Spirit create and empower the church. This is what John Webster called the “trinitarian deduction of ecclesiology,” and it provides a clear account of God and the church as intimately connected but rightly ordered.
Much more could be said. And in fact I said much more in a chapter I recently turned in for a forthcoming edited volume on ecclesiology. I’ll share information about that volume here when it’s available.