That is explicitly what they say.
Quite so!
Saying it doesn't make it so. If, when you stand before God, you discover that your doctrine here is false, you discover simultaneously that this statement was blasphemy. I suggest you be more careful with your words.
You do see it because I just show it to you. Your declaring it not so doesn't change the what the scripture explicitly states and there's quite a lot of similar passages, by the way. It's sort of a theme throughout the Old Testament and Genesis in particular.
HA! That's a laugh!
You're the only Calvinist I've ever encountered that tried to deny such well established history. It's only recorded in Augustine's own writings.
Well, when you live in an echo chamber you only hear what you like to hear. Deny it all you want, it doesn't change the facts.
Augustine's mother tried for years to get him to become a Christian and he refused specifically because the bible teaches that God can change.
The idea that God cannot change (including changing His mind) comes from Socrates, whom we learn about through Plato and Plato's student Aristotle, whom Augustine really really loved when he was young.
From Plato's Republic Book II, Socrates says to Adeimantus...
"And what do you think of a second principle? Shall I ask you whether God is a magician, and of a nature to appear insidiously now in one shape, and now in another --sometimes himself changing and passing into many forms, sometimes deceiving us with the semblance of such transformations; or is he one and the same immutably fixed in his own proper image?
I cannot answer you, he said, without more thought.
Well, I said; but if we suppose a change in anything, that change must be effected either by the thing itself, or by some other thing?
Most certainly.
And things which are at their best are also least liable to be altered or discomposed; for example, when healthiest and strongest, the human frame is least liable to be affected by meats and drinks, and the plant which is in the fullest vigour also suffers least from winds or the heat of the sun or any similar causes.
Of course.
And will not the bravest and wisest soul be least confused or deranged by any external influence?
True.
And the same principle, as I should suppose, applies to all composite things --furniture, houses, garments; when good and well made, they are least altered by time and circumstances.
Very true.
Then everything which is good, whether made by art or nature, or both, is least liable to suffer change from without?
True.
But surely God and the things of God are in every way perfect?
Of course they are.
Then he can hardly be compelled by external influence to take many shapes?
He cannot.
But may he not change and transform himself?
Clearly, he said, that must be the case if he is changed at all.
And will he then change himself for the better and fairer, or for the worse and more unsightly?
If he change at all he can only change for the worse, for we cannot suppose him to be deficient either in virtue or beauty.
Very true, Adeimantus; but then, would any one, whether God or man, desire to make himself worse?
Impossible.
Then it is impossible that God should ever be willing to change; being, as is supposed, the fairest and best that is conceivable, every god remains absolutely and for ever in his own form.
That necessarily follows, he said, in my judgment."
Augustine take this same thought process and applies it to God's mind...
From Aristotles' "Metaphysics" book XII...
"The nature of the divine thought involves certain problems; for while thought is held to be the most divine of things observed by us, the question how it must be situated in order to have that character involves difficulties. For if it thinks of nothing, what is there here of dignity? It is just like one who sleeps. And if it thinks, but this depends on something else, then (since that which is its substance is not the act of thinking, but a potency) it cannot be the best substance; for it is through thinking that its value belongs to it. Further, whether its substance is the faculty of thought or the act of thinking, what does it think of? Either of itself or of something else; and if of something else, either of the same thing always or of something different. Does it matter, then, or not, whether it thinks of the good or of any chance thing? Are there not some things about which it is incredible that it should think? Evidently, then, it thinks of that which is most divine and precious, and it does not change; for change would be change for the worse, and this would be already a movement."
I could go on multiplying quotes here but I think the point is made. If you believe that God is immutable and/or that God cannot change his mind, it is because of these specific passages from Plato's Republic and Aristotle's Metaphysics and others like them.
Augustine took this precise teaching a imported it into the church through his "Confessions".
From Augustine's "Confessions" Book V...
"This was especially clear after I had heard one or two parts of the Old Testament explained allegorically--whereas before this, when I had interpreted them literally, they had “killed” me spiritually."
Augustine is speaking there of the teaching of his mother's bishop, Bishop Ambrose of Milan.
From Book VI chapter IV....
"I was also glad that the old Scriptures of the Law and the Prophets were laid before me to be read, not now with an eye to what had seemed absurd in them when formerly I censured thy holy ones for thinking thus, when they actually did not think in that way. And I listened with delight to Ambrose, in his sermons to the people, often recommending this text most diligently as a rule: “The letter kills, but the spirit gives life,” while at the same time he drew aside the mystic veil and opened to view the spiritual meaning of what seemed to teach perverse doctrine if it were taken according to the letter."
Do you see what he's saying there? He rips II Corinthians 3:6 completely out of its context and instead of teaching that its the law that kill but God who gives life, which is what the passage is actually teaching, and instead uses it to say that the bible aught not be taken literally but figuratively - whenever it says anything in contradiction to Plato or Aristotle. And he's talking here about how this teaching from Ambrose is what began to change his mind about Christianity.
Augustine continues...
From Confession Book VII chapter III
"But as yet, although I said and was firmly persuaded that thou our Lord, the true God, who madest not only our souls but our bodies as well--and not only our souls and bodies but all creatures and all things--wast free from stain and alteration and in no way mutable, yet I could not readily and clearly understand what was the cause of evil. Whatever it was, I realized that the question must be so analyzed as not to constrain me by any answer to believe that the immutable God was mutable, lest I should myself become the thing that I was seeking out (i.e. the cause of evil)"
Here Augustine tells us explicitly that he standard is the immutability of God. He is saying that he will except no explanation for the problem of evil that suggests that God can change. The point being that he was never able to find such an answer in the bible but found his answer in the teachings of Bishop Ambrose.
Okay, so, once again, I could go on and on multiply quotes here but the point is made and the history is clear, well established and totally undeniable. There is a straight and unbroken line that starts with Socrates goes through Plato and Aristotle to Ambrose of Milan to Augustine of Hippo to Martin Luther (an Augustinian monk) and Calvin to every Calvinist today that believes and teaches this stuff.
Those of you who desire to read a more complete and fully documented treatment of this same topic. I strongly recommend reading the following article by the late Pastor Bob Hill...
Calvinism Unmasked by Bob Hill
