This post is pure speculation!
I have been pondering the doctrine of immutability. Here are a couple of things I think I think.
This is sort of the bare bones minimum. Our faith would be pointless if it were in something for which the rug could be yanked from under our feet. I cannot possibly fathom why anyone would even contemplate worshipping a deity who was not trustworthy, and God’s trustworthiness depends on the fact that, contra Nietzsche, He won’t die on us and He won’t break his word. There is then no disagreement that I can imagine on the twin assertions that God’s aliveness is immutable and God’s integrity is immutable.
God is not just eternal, he is “fullness in being” not “becoming,” and it is in this sense that He is both immutable and impassive.
As a consequence, no act of God’s creatures cannot add or subtract from him.
The difficulty with more advanced immutability is that by all appearances God is quite mutable. I’m not talking about statements regarding God “changing His mind”, which we can attribute to a necessity (because we are finite) of relying anthropomorphic language. We can look at classic Reformed teachings that are not generally explained as anthropomorphic, most obviously the common teaching that we are justified at a moment in time.
From our perspective, there was period in which God regarded us by our (inadequate) righteousness—but the next instant he regarded us by Christ’s perfect righteousness. That’s a very big change, (again, from our perspective) --a very consequential mutation at an instant in time.
There are solutions to this problem, if it is a problem. I’ve come to believe that they are variations on the same theme, namely of God’s transcendence. His out-of-timeness. In God’s physics (and I’ll further speculate, because that’s all this is--pure speculation, in our physics in Glory as well) there is no arrow of time, no second Law of thermodynamics.
In this view, which of course I didn’t invent, God can (immutably) judge us as righteous and unrighteous, for time is axis upon which God can stroll (that's anthropomorphic!) in either direction. Our perspective, however, is a specific (and inexorably moving in one direction) time-slice through God’s—in which God’s immutable view of us has the appearance of changing. In fact, most of what is (I believe) too trivially dismissed as anthropomorphic language might actually be explained better as our reduced dimensional view of God's extra dimensionality.
The reason I don’t like "it's anthropomorphic" used as a rather blunt instrument is that to me it implies that the Holy Spirit inspired a tremendous amount of scripture that does not even come close to meaning what it says. In fact, my initial rejection of the doctrine of Impassibility was based, for the most part, on what I viewed as an unsatisfying tendency to relegate an enormous quantity of scripture to the relative dust bin (too harsh, but you hopefully get that I mean) on the basis of an argument-ending declaration of anthropomorphism. Like many others I believed (and still believe) that the text regarding God's mind-changing or changing emotion is, yes, anthropomorphic, but not to the extent that is is virtually meaningless. I feel more comfortable believing that God’s described change in disposition toward Israel reflects our reduced dimensional time-slice rather than “it’s just anthropomorphic." Yes it’s anthropomorphic, but it’s anthropomorphic with some bite to it. If God is extra dimensional, then I can grasp both immutability and impassibility. I'm going to hold on to the extra-dimensionality view of God's domain, even if only as a personal metaphor to help me feel comfortable.
"...I don't have the answer but I wonder..."
- You will never have an answer, you will end up going crazy if you try this too much.
- Remember that just like the concepts themselves (such as motion, time and space) you yourself are part of the creation of God, therefore you will never have a true point to compare outside of this without "outside knowledge" to the creation itself (" all"). And possibly only your very existence (your soul) would be worth that knowledge and I'm sure you do not want it to be considered destroyed by putting it out of creation without the help of a higher power, but with what purpose would you really put at risk a part of the God's creation.