Some theologians, acting I suspect from a somewhat superficial understanding of the doctrine [of divine impassibility], have wished at time to reject apatheia as an alien import from Greek metaphysics. But it is not, I would assert, a negotiable doctrine: the very rationality of the gospel requires it. This is not to ignore the anxiety that the word “impassibility” can occasion; for some, it seems to suggest a God who is “unfeeling” (in the colloquial sense) and therefore “uncaring.” And obviously it is difficult for us to avoid imagining God in terms of finite psychological subjectivity, and so thinking of him as someone who “experiences” a reality set over against him, and who therefore knows things by way of contrasts and limits. When we allow this habit of thought to become something like an intellectual conviction, however, we become guilty of both an infantile anthropomorphism and a philosophical catachresis. This is especially true when we think of God as requiring “passions” to love us, as loving us “responsively,” as indeed “needing” us. No doubt such language gives us a sense of our own significance, and certainly it accords with our own experiences of love; but it also effectively denies the transcendence of God and the plenitude of his charity. In fact, it dissembles the very nature of love; for love is not—in its inmost essence—a reaction. In God, who is its transcendent origin and end, it is the one infinite and changeless act of being that makes all else actual, and so is positive, sufficient in itself, and without any need of contrariety to be fully vital and creative. As Trinity, God always already possesses the fullness of charity in himself—difference and regard, feasting and fellowship, perfect delight and perfect rest—and has no need of any external pathos to waken or fecundate his love. We are not necessary to him: he is not nourished by our sacrifices or ennobled by our virtues, any more than he is diminished by our sins and sufferings. This is a truth that may not aggrandize us, but it does, more wonderfully, glorify us: for it means that, though he had no need of us, still he loved us when we were not. And this is why love, in its divine depth, is apatheia.
The failure to embrace the idea of divine impassibility becomes especially disastrous for Christians when it causes them to think of the crucifixion as an event in the genesis of God’s personality, a trial through which he passes as our fellow sufferer so that he could achieve in himself the perfection of self-abandoning love. At its most vulgar, this way of thinking implies that God took our suffering into himself as something that changed or enlarged his knowledge of us, and it implies also that on the cross he had to learn the extent of our suffering: now, perhaps, he understands what we must endure. This is simply nonsense. It is a logical absurdity simultaneously to assert that God is the source of all that is and that God can “become” something more or other than he previously was. To suggest that God becomes the God he is by suffering passions, according to encounters with other and tragic realities (even if he creates those realities), is to trade in mythology, to preach a finite God, one who is no doubt a “supreme being” but not the source of all being. And if God’s love were in any sense shaped by sin, suffering, and death, then sin, suffering, and death would always be in some sense features of who he is. This not only means that evil would be a distinct reality over against God, and God’s love something inherently deficient and reactive; it also means that evil would be somehow a part of God, and that goodness would require evil to be good. Such a God could not be love, even if in some sense he should prove to be “loving.” Nor would he be the good as such, nor being as such. He, like us, would be a synthesis of death and life.