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Christ the Key
By Kathryn Tanner
Cambridge, 309 pages, $29.99


Far too much of what is published under the name of theology these days has about it the air of the frivolous—but such a complaint cannot be made about the work of Kathryn Tanner. Since her 1988 God and Creation in Christian Theology , she has produced a steady series of books that explore theology and the relation of theology to social science. In 2001 she published Jesus, Humanity, and the Trinity , which was systematic in laying out a comprehensive theological vision but so brief that it called out for greater elaboration. Christ the Key is her first payment on the promissory note of that earlier book.

The thesis of this new book is stated in the title: “Christ is the key . . . to what God is doing everywhere.” Such a claim is hardly new, but Tanner believes a right understanding of Jesus (and of what God accomplishes in Jesus) can throw new light on theological topics.

For Tanner, what is decisive about Jesus is that, through the Word taking on human nature in the Incarnation, humanity is itself purified from sin—and given what, by nature, is beyond it: participation in the life of God. The key to Tanner’s Christology is Incarnation, understood not simply as an event that takes place at Jesus’ conception but as the permeation of the human nature assumed by the Word—a permeation completed only in the Resurrection and Ascension. Christ is then the key to all else.

Christ the Key is less a single, overarching argument than a series of closely connected studies of how a particular understanding of Christ reshapes various theological topics. Tanner begins with an extended discussion, stretching over three chapters, of human nature as oriented from the beginning by grace to the image of God, the second person of the Trinity. Humanity is created for the grace that opens the divine life, and, without grace, human nature cannot function well. The following chapters explain how this understanding of Christ sheds light on the intra-relations of the Trinity, political theology, atonement and sacrifice, and the working of the Spirit in the world.

Tanner draws extensively on the Greek Church Fathers (especially Athanasius and the Cappadocians) and on Augustine to make her case. Her writing, while on occasion dense, is clear. The occasional density comes from her discussing hard questions in close detail. Her discussion of how the Gospels’ narratives provide a template for understanding the relations among the persons of the Trinity is brilliant: a model for the theological use of Scripture. In the chapter on politics, she analyzes the weaknesses of political theologies that seek to make the inner life of the Trinity a paradigm for human communal life, pointing out that such approaches lead to bad theology and vague political recommendations.

To say that Christ the Key is strikingly well done, however, is not to say that it is right. Again and again, I was forced to wonder whether Tanner sees rightly the integrity of the human creature and the structure of human agency in relation to God. Taking up the important but subtle Catholic debate of whether human nature is oriented to grace by a natural desire for grace, she cuts the Gordian knot by rejecting the entire Thomist-Aristotelian terminology of desires rooted in human nature. Rather than arising from human nature, the desire for God comes from God’s gracious presence, a presence necessary for human well-being. The issues here are subtle, but I wonder whether the integrity of the creature has been given its due.

More problematically, the assumption of human nature by God in Christ seems, for her, to be straightforwardly redemptive for everyone who shares that nature. “Christ is one with us in virtue of our humanity whatever we might do . . . . Via the hypostatic union, we are wrapped around with something we cannot get rid of, something that therefore inevitably makes itself felt in all that we go on to become.” We are justified not by faith or the sacraments, but by the Incarnation itself: “The incarnation of the Word in human flesh, in other words, is the primary form of God’s own attachment to us by which we are justified . . . . Faith is something that is going on in us as a result of our being justified through attachment to Christ and the gift of the Spirit thereby.” Tanner explicitly rejects the possibility that faith or love are what attaches us to Christ, since either view unduly elevates a human action.

What she seems to be saying is not only that the Incarnation brings about a change in the objective situation of every person but that the Incarnation also redeems and justifies all persons. (I say seems because she never quite puts the assertion this flatfootedly, and she does make passing reference to baptism uniting us to Christ.) Nonetheless, in Christ the Key , the moment of human appropriation becomes a matter of sanctification, something not intrinsic to justification. Such an assertion disagrees not only with the Council of Trent but also with the Protestant Reformers and, I would think, the clear meaning of Scripture. Has the element of human interaction with God fallen away before a divine unilateralism?

The same worry crops up in Tanner’s discussion of atonement and sacrifice. She wants to do justice to criticisms of penal and forensic understandings of the Cross, and she offers a nuanced account of the saving significance of the Cross within her own Incarnation-centered scheme. The Cross—where the incarnate Word takes on human sin in its depth and purifies it—is about overcoming and even sanctifying death. In a sense, the Cross is the culmination of the Incarnation’s encounter with a sinful world.

What Tanner rejects is any notion that the Cross also has an orientation back toward God, as, for instance, a satisfaction of divine justice (or the satisfaction of an aspect of God’s creative intent for humanity, Anselm’s real point). Such a rejection is not uncommon in modern theology, but it overlooks the significance of human sinfulness as responsible action, an action that even God takes seriously. (In line with Tanner’s overall outlook, the introduction of sin into humanity is seen as a function of human immaturity when the gifts of grace are first given.) In truth, while Western Christianity may have relied too heavily on juridical categories in the past, such categories express an essential point about human agency and its responsibility.

Curiously, the problem in Tanner’s theology is the consequence of one of its strengths. Since her first book, Tanner has consistently and skillfully spelled out a noncompetitive understanding of divine agency. Divine and human agency operate at different levels of reality, so that God can be at work within human agency without violating its freedom. In the Joseph story in Genesis, God brings about his purposes by working within the network of human causes; God never becomes a character within the story with whom other characters interact.

But the biblical picture of God and humanity also includes real interaction: Adam and Eve sin, and God casts them out of the Garden; Abraham argues with God about the fate of Sodom and Gomorrah”and, in that interaction, God’s agency is seen as distinct from human agency.

Interaction is a sign of divine condescension and also a sign of the significance of human action for God. How to hold together these two pictures of divine agency, noncompetitive and interactive, is a deep problem for Christian theology. Kathryn Tanner’s theology, precisely because of its real strengths, is a witness to the effects of systematically underplaying one side of the Bible’s double vision of how God and humanity relate.

Michael Root is professor of systematic theology at Lutheran Theological Southern Seminary in Columbia, South Carolina.