(For theological nerds the argument here is basically this. If God can be acted upon God becomes a part of the furniture of the universe, an agent among agents. God, in that instance, would no longer be God but a Supreme Being within the universe. This God cannot be, for, as the Ground of Being, God cannot be "within" the universe as a being among beings.)
Of course, the pushback here is that a God that doesn't suffer with us isn't the God we find in Jesus. God isn't impassive but emotionally invested.
I don't want to rehash this debate. Use Google to go down this rabbit hole if you'd like. What I want to do is revisit a post of mine from 2018.
Specifically, in that post I argued that divine impassibility has a branding problem. When we think of God being "impassive" we think of God being emotionally blank, flat, or indifferent. And, of course, we recoil at this vision of a cold, impassive God.
But as I argued in 2018, that's not who God is. God is love. And it's this love that is sturdy, fixed, unwavering, and unchanging. God is "impassive" in the sense that God's love doesn't ebb or flow, rise or fall, come and go. God's love isn't triggered into existence only to fade back into indifference. God's love is like the sun, always burning and constant, and never changing in the face of human action.
Yes, it is true, that the word "impassive" doesn't conjure up this image, which is why I said the doctrine of divine impassibility has a branding problem. It's just a poor word choice. But if we're careful to define "impassive" as unchanging rather than unemotional, then we have a better chance of understanding what the doctrine is trying to teach us.
Anyway, I wrote that post in 2018 but was recently pleased to come across an essay by David Bentley Hart that makes this exact same argument.
As Hart shares, the word used to argue for divine impassibility was apatheia, a word borrowed from the Greeks:
Apatheia entered Christian thought [as a term] borrowed primarily from the Stoics, for whom it signified chiefly a kind of absolute equanimity, an impassive serenity so fortified by prudent self-restraint against any excesses of either joy or sorrow as to be virtually indistinguishable from indifference.
This is another branding problem, as apatheia is the word where we get "apathy" from, and that's just not the word we want to ascribe to God. But as Hart goes on to observe, Christian thought radically rethought apatheia, connecting it not to stoical indifference but to agape. As Hart writes,
When Christians adopted the term [apatheia], however, it became something much more. According to Clement of Alexandria, for instance, true apatheia consists of the cultivation of understanding and charity, and as we are drawn to God in Christ, we are being conformed to a God who is without pathe--devoid of pain, free from wrath, without anxious desire, and so on--not as a result of having mastered the passions within himself, but from his essence, which is the fulness of all good things; and ultimately the Christian who has so advanced in understanding as to be purged of emotions is one who has become entirely love: a single inexorable motion of utter agape. Far from being mere Stoic detachment, then, apatheia is in fact a condition of radical attachment.
Now the question that will get asked here is this, "Isn't love an emotion?" To which Hart responds:
To state the matter simply--no: love is not primordially a reaction, but the possibility of every action, the transcendent act that makes all else actual; it is purely positive, sufficient in itself, without the need of any galvanism of the negative to be fully active, vital, and creative. This is so because the ultimate truth of love is God himself...And this is why love, when it is seen in its truly divine depth is called apatheia. If this seems an odd claim to us now, it is largely because we are so accustomed to thinking of love as one of the emotions, one of the passions, one of those spontaneous or reactive forces that rise up in us and spend themselves on various objects of impermanent fascination; and of course, for us "love" often is just this. But, theologically speaking, at least according to the dominant tradition, love is not, in its essence, an emotion--a pathos--at all; it is life, being, truth, our only true well-being, and the very ground of our nature and existence.Phrased simply, love isn't a feeling, love is ontology.