I think it would be more accurate to say that God’s love wasn’t expressed as wrath until someone sinned (whoever that first sinner was), and did so in a way that (in God’s judgment) required wrath as the best expression for achieving God’s goals in regard to the sinner.
The notion here is that there might easily be other proper actions by God in relation to a person’s sin, depending on the circumstances. To give what should be the most obvious immediate example, God doesn’t immediately annihilate sinners, or allow them to annihilate themselves by their choice of sinning, the moment even the ‘smallest’ sin is committed; but graciously keeps even the worst possible sinners in existence for at least some created time afterward. Even annihilationists have to admit this–assuming they acknowledge that only God can exist without continual upkeep from anything other than God. Which theists often forget to acknowledge, even when they would otherwise agree with that, leading to what amounts to proposing that sinners exist independently of God (which in turn is a tacit if accidental rejection of supernaturalistic theism, including ortho-trin.)
Annihilationists, by definition, are usually better than other Christians about keeping the conditional existence of derivative creatures in their theologies. (Which, not incidentally, is why some annis like our guest Glenn prefer to call their position “conditional immortality”–as if non-annihilationists necessarily denied the conditional existence of derivative creatures. Plus it just sounds more positive than “annihilationism”. )
I have, however, run across at least two annihilationists in my experience (one of whom was a professional theologian arguing in favor of annihilationism) who ended up, for different reasons, having to propose that the condemned sinners aren’t annihilated by God after all. In one case, the sinners keep existing as something loathsome to gross out the redeemed into eternity as an example of evil–which if the sinners cease existing as persons rather sounds like it is the redeemed, not damned sinners, who suffer at least a little Eternal Conscious Torment! In the other case, sinners had to be speculated to keep existing after annihilation, as persons, in order to try to claim that God wasn’t violating their personhood, which wouldn’t be loving toward them.
Come to think of it, C. S. Lewis (whom I think can be considered to count as a professional theologian in some significant way ) also speculated, at one point (while writing The Problem of Pain) that annihilated sinners keep existing at right angles (so to speak) of the natural time they would have otherwise inhabited. (The visual metaphor would be like a paintball splattering against a wall rather than continuing its flight forward spatially.) He seems to have dropped that later, though; at least, I don’t recall him ever mentioning that final fate again in subsequent writing (which there was a lot of, including The Great Divorce and The Last Battle where there were plenty of opportunities to promote that idea again. But impenitent sinners just poof finally out of existence in each case.)
Anyway: the continuing existence of sinners for at least some time after sinning, is directly dependent on the grace of God toward and for the sinner. And it’s going to be reaaaaally hard to coherently argue that this grace isn’t an action of God’s love toward and for the sinner. Certainly I would argue it is, as an ortho-trin theist!
So the very first action of God toward the sinner as a ‘sinner’ per se, is still an action of love and grace which isn’t an expression of wrath per se (or not yet anyway): sinners exist, even as ‘sinners’, because God loves sinners, too. He just doesn’t love their sin. (And will take steps accordingly.)