Does God change his mind? How can we reconcile the passages of Scripture that seem to indicate that he does with his omnipotence and infallibility? Charnock writes:

   Prop. III. Repentance and other affections ascribed to God in Scripture, argue no change in God. We often read of God’s repenting, repenting of the good he promised (Jer. xviii. 10), and of the evil he threatened (Exod. xxxii. 14; John iii. 10), or of the work he hath wrought (Gen. vi. 6). We must observe, therefore, that
   1. Repentance is not properly in God. He is a pure Spirit and is not capable of those passions which are signs of weakness and impotence, or subject to those regrets we are subject to. Where there is a proper repentance there is a want of foresight, an ignorance of what would succeed, or a defect in the examination of the occurrences which might fall within consideration. All repentance of a fact is grounded upon a mistake in the event which was not foreseen, or upon an after knowledge of the evil of the thing which was acted by the person repenting. But God is so wise that he cannot err, so holy he cannot do evil; and his certain prescience, or foreknowledge, secures him against any unexpected events. God doth not act but upon clear and infallible reason; and a change upon passion is accounted by all so great a weakness in man, that none can entertain so unworthy a conceit of God. Where he is said to repent (Gen. vi. 6), he is also said to grieve; now no proper grief can be imagined to be in God. As repentance is inconsistent with infallible foresight, so is grief no less inconsistent with undefiled blessedness. God is “blessed forever” (Rom. ix. 8), and therefore nothing can befall that can stain that blessedness. His blessedness would be impaired and interrupted while he is repenting, though he did soon rectify that which is the cause of his repentance. “God is of one mind, and who can turn him? what his soul desires that he doth” (Job xxiii. 13).
   2. But God accommodates himself in the Scripture to our weak capacity. God hath no more of a proper repentance, than he hath of a real body; though he, in accommodation to our weakness, ascribes to himself the members of our bodies to set out to our understandings the greatness of his perfections, we must not conclude him a body like us; so, because he is said to have anger and repentance, we must not conclude him to have passions like us. When we cannot fully comprehend him as he is, he clothes himself with our nature in his expressions that we may apprehend him as we are able, and by an inspection into ourselves, learn something of the nature of God; yet those human ways of speaking ought to be understood in a manner agreeable to the infinite excellency and majesty of God, and are only designed to mark out something in God which hath a resemblance with something in us; as we cannot speak to God as gods, but as men, so we cannot understand him speaking to us as a God, unless he condescend to speak to us like a man. . . .
   3. Therefore, repentance in God is only a change of his outward conduct, according to his infallible foresight and immutable will. . . . it is a change of events, not of counsels. Repentance in us is a grief for a former fact, and a changing of our course in it; grief is not in God, but his repentance is a willing a thing should not be as it was, which will was fixed from eternity; for God, foreseeing man would fall, and decreeing to permit it, he could not be said to repent in time of what he did not repent from eternity; and therefore, if there were no repentance in God from eternity, there could be none in time. But God is said to repent when he changes the disposition of affairs without himself; as men, when they repent, alter the course of their actions, so God alters things, extra se, or without himself, but changes nothing of his own purpose within himself. It rather notes the action he is about to do, than anything in his own nature, or any, change in his eternal purpose. . . .

—Stephen Charnock, The Existence and Attributes of God (Baker Books, 2005), 1:340–342