What about G-d changing because He chooses to? Or are you unwilling to attribute volitional power to Him?
If God 'changes' he doesn't really change though, does he. Being perfection, ie. complete, he holds all possibilities within himself, therefore cannot really change. What could he change into, that he was not already?
Just so you know, I did understand what Thomas was getting at. I was actually quite pleased that I agreed with him on something.
And you yourself say that time, a created nature, has the ability to change God. Well, there ya go. You admit yourself that you believe that nature can change God. You also wrote that he may be growing more perfect through his creation. That would mean that nature--his creation--would be changing him. So, I can definitely see where Thomas is coming from. And I agree with him. Perfect is perfect, it can not be made more perfect, or it wouldn't have been perfect in the first place.
Thomas should tell you that humans' idea of G-d's perfection and immutability is an "anthropomorphism." But he won't. (He reserves that charge only for doctrines he doesn't like.) Since he won't, I will.
I don't see how you get that. The reality of completion is decidedly not a human trait, even if the idea is an idea had by humans, therefore calling something perfect, or complete, is in no way anthropomorphizing it.
As I write this, the question poses itself, if there was no time and no space before the universe, will there be a time and space after the universe? I should think not ... which argues against the successive theory ... ? Just a thought ...
Well, there is no time and space during the universe, unless you are subject to time and space, lol. But if there is an everlasting succession, I don't see how the universe would end, therefore, I don't see how time would stop. And like I said, which universe was the first, which before it there was no time or space? We have no way of knowing that it was this version of the matter (aka, the universe in which we reside, lol). This is really fascinating, actually...
The Incarnation represents a covenant, too - sometimes called the Covenant of Grace. The Incarnation is considered a singular event. It would have to have been an event that changed G-d because it modified the Trinity. A possible way around this is to assert that Jesus was not part of the Trinity.
If God is in time. But, being out of time, the incarnation would be a part of God from the beginning, as there would be no time when it was not a part of God, as there would be no time.