So-called open theism denies that God has ordained the course of events; rather, he is "open" to the future and adapts to human decisions. But this view undermines the very Christianity that it wants to maintain. This is true for at least two reasons.

First, any view that minimizes or reduces God's "God-ness," including his absolute sovereignty over his creation, appeals directly, though subtly, to our sinful hearts. We long to be autonomous. We long to have God at our beck and call, and then to offer him worship once he is domesticated. One of the primary lessons of church history is that to attribute absolute sovereignty to God is difficult, both mentally and spiritually. The view that God has given up his sovereignty for our sakes has, regrettably, been predominant in Christian history. Conversely, it has been unpopular and taxing to hold fast to the teaching of God's absolute sovereignty.

Second, behind a mask of concern for biblical truth, a supposed rejection of Greek ideas, and an attempt to emphasize God's relationality, lies either an ignorance or perhaps even a rejection of the controlling motifs of Scripture (and thus of theology)—motifs that have demonstrated the beauty of orthodoxy while at the same time motivating the saints through the ages to worship and praise God for who he is. The god of open theism is not to be praised, but pitied; he is a pathetic excuse for a god, one that would fit well within the ancient Greek pantheon. A dose of Reformed Christology is needed to correct this error.

In order for God to relate to us, in order for there to be a commitment on the part of God to his people and more broadly to his creation, there had to be a "voluntary condescension" (WCF 7.1) on his part. This is the covenant principle. We see it in Exodus 3, where the burning bush is a sign, a "parable" revealing who God is. It expresses both divine independence (aseity) and a covenant relationship. This covenant principle is, in one sense, quite basic to our understanding of Scripture. It is the principle that we must use in order to understand just how it is that God can remain who he is while at the same time interacting with his creation.

Let us, then, take seriously the fact that our Christology organizes our understanding of God's relationship to creation. How, specifically, does the person of Christ help us to understand who God is and how he relates to us? We can elaborate on that understanding by looking briefly at Philippians 2:5-8.

We should recognize at the outset that we do not do justice to this passage simply by concentrating on its Christology. The point the apostle is making by way of Christology has to do with our own sanctification; he wants us to model the behavior exemplified by Christ, specifically the behavior that culminated in Christ's incarnation. Given our present concerns, however, we will focus our attention on the Christology at hand.

What does Paul mean when he says that Christ was "in the form" of God? The word form communicates two analogous, though not identical, situations. The "form of God" is further explained to mean that Christ is equal to God. But, Paul is not immediately concerned in this passage to give us a Christian-theistic ontology. He is concerned to present to us the quintessential example of how we, as the Lord's people, are to think and live. So Paul uses the word form in the expression "form of a servant" to refer, not so much to the being of Christ, but to his status as incarnate. In that case, form expresses the role that Christ accepted when he agreed to be "born in the likeness of men."

The implication of this text is that the preincarnate Son of God, as the second person of the Trinity, determined voluntarily to come down in such a way that he would identify himself with humanity. He came by taking on our likeness and by taking the role of a servant of the Lord.

What then does Paul mean when he says that this preincarnate Son, who was in the form of God but who took on the form of a servant, "made himself nothing?" Here controversy has raged, especially since, in some translations, the phrase is (properly) translated as "emptied himself" (NASB). Paul explains what he means when he notes that this self-negation had to do with the fact that Christ did not regard his equality with God "a thing to be grasped."

In this context, it becomes clearer to us what Paul is saying about our Savior. In his decision to take on the likeness of humanity, he did not simply look to his own position and status, nor did he count that position and status something that he should, in every way, maintain. Rather, he considered the position and status of those who are lower, who could not reach up to his position, and he determined, in his grace, to stoop down to their level.

The Key: One Person, Two Natures

Christ did not empty himself of something. Rather, he emptied himself by becoming something that he was not previously—something that, by definition, required humility and ultimately humiliation (Phil. 2:8). For Christ to make himself nothing, says Paul, was for him to humble himself, and he humbled himself by being born in the likeness of men and by becoming obedient to the point of death. His self-emptying was, in point of fact, therefore, a self-adding. He added a human nature, so that we might be redeemed.

Christ made a decision—a decision of humiliation. He did not have to humble himself; he had every right to continue without adding to himself the humiliating status of humanity. But he determined not to. The one who is equal to God, who is in the form of God, who is himself God (John 1:1), did not stop being God (such a thing would be impossible), but rather took on something that he previously did not have. He took on human nature (John 1:14).

So the second person of the Trinity remained God while coming down to be the God-man. This is the covenant. And, as the Westminster Confession reminds us, Christ is the substance of the covenant (WCF 7.6; WLC 35; cf. Col. 2:8ff.).

This Christology is nothing new. Any cursory glance at the church's position on the hypostatic union will bring out the same points. Moreover, the Chalcedonian Creed provides ample evidence that the thinking of open theism is fatally deficient. That creed reminds us that the Incarnation has never been seen as God's abandoning of any of his attributes at all. As a matter of fact, it is in the Incarnation that we begin to see how it is that God can relate to his creation without becoming less than God. The creed affirms that the Son of God, as God, is to be "acknowledged in two natures inconfusedly, unchangeably, indivisibly, and inseparably." The creed goes on to affirm, concerning this hypostatic union, that, with regard to these two natures, "the distinction of natures [is] by no means taken away by the union, but rather the property of each nature [is] preserved, and concurring in one Person and one Subsistence, not parted or divided into two persons, but one and the same Son, and only begotten, God the Word, the Lord Jesus Christ."

If we take the Chalcedonian Creed seriously (and the church, both Catholic and Protestant, has done so since the creed was written), then the theological priorities of our thinking in this matter become clearer to us. First, it should be clear that there are two crucial concepts in the creed, and thus in our thinking about God and his relationship to us, that define the parameters of how we are to understand God's accommodation to us. Those two concepts are "person" and "nature."

For open theists, person and nature are virtually identical. To the extent that God takes on the nature of created reality, he must be subject to (different aspects of) creation. Historically, however, in orthodox theology, priority has always been given to "person" over against "nature." The reason this is so is that what belongs to "person" is independent and individuated in a way that what belongs to "nature" is not. God's accommodation presupposes that he was (triune) person before coming down to the created level. It is for this reason, it seems to me, that theology has historically attempted to delineate who God is, quite apart from his accommodation, in order thereafter to explain God's accommodation itself. God, as we have seen him in the Old Testament, or the second person of the Trinity, as we see him more clearly in the New, is a person with distinct characteristics and attributes prior to his accommodation to and with his creation.

While there are careful distinctions here that must be maintained with respect to God (for example, that God's essence is identical with God himself), there is no question that orthodox Christology always taught that God came down in the second person of the Trinity, who was and remains fully God, and he took on a human nature without thereby in any way changing his essential deity. To think, as open theists do, that, because God interacts with creation he must necessarily change or in some way limit his essential deity, is, in effect, to fail to see the Incarnation for what it is. (It is also to deny the unfathomable mystery that just is "God with us.") While we cannot comprehend just what it means to possess both a divine and a human nature, we must affirm it in order for the gospel, in its fullest biblical sense from Genesis to Revelation, to be what it is.

The author, an OP minister, is professor of apologetics at Westminster Theological Seminary in Philadelphia. He quotes the ESV. This is a substantially edited version of his article "Most Moved Mediator," which appeared in Themelios, Autumn 2004. Reprinted from New Horizons, January 2007.