Does the Bible contradict itself about whether God changes His Mind or not?
Some verses in the Bible are unequivocal about the fact that God does not change His mind. We'd expect this from an omniscient deity and this is the position I take - God indeed cannot change His mind in the sense that He doesn't need to. In an ultimate sense, God cannot change it and cannot want to change it, because His omniscience prevents Him from not knowing whether He'd disagree with Himself in the "future" or any new information that He previously did not know. This includes if He would decide to no longer be merciful, even if it happens at some point in the "future", because He'd have known this from the very beginning of time that He'd change His mind and planned it.
Dan Barker in numerous debates claims this is proof against both God's omnipotence as well as His ability to have a free will. This is a fallacy from language in the first case and a misunderstanding of causality in the second as we'll show.
The question becomes a bit more involved. God is omniscient and therefore with respect to Himself He does not change His mind. However, is it true that God would punish a truly wicked in his heart man - in this life or the next? Yes, right? And this cannot be some kind of "pretend" intent on God's part. But is it also true that God would forgive and not punish the same man if he repented? We have to agree again. If these answers are opposites and God is genuine in His decisions in each case, how does this fly with our original thesis? Unless they're some kind of "joke", verses like Jonah 3:10 and Ezekiel 18:21-24 imply as much.
What this all boils down to is that, as ethicists starting with John Dewey realized long ago, space and time have no relation to intent. If this man were given all the options and situational details that led him to change his character one way or another, he'd have logically (and deniers of free will especially cannot disagree here) picked one way or another forever. God, knowing this, would logically and obviously respond one way. And since God does know this ultimate choice, He brings about the circumstances that would expose it here on Earth for all as evidence (Luke 12:3). It is only with respect to the illusion of "circumstance" or space-time that these things can be missed.
Therefore, while God can never change His mind in its essence, from our point of view He genuinely, in every sense of the word, up to His metaphysical self, changes it. A little bit like purposefully losing a game of soccer to your baby brother - you technically did lose, but not really.
Another way to look at it is using the Monty Hall Problem. When you first pick a door, your chance is 33% regardless of which door you pick. When a false door is eliminated, your chance doesn't become 1/2 but the door you picked is still at 33% chance of winning, with the other door being 66%! This is because one has introduced time and opportunity into the equation. The false door that was removed as a choice never had a real chance of winning - neither does the other whether you've picked it or not. But with respect to you and your knowledge it's 1/3. And this value is very real mathematically, even if one assumes determinism in the universe, because you're real and so is your limited knowledge.
Another way to think of it is the equation: 2+2=4. Isn't it the case that this is true "before" and "after" the two 2's are added? One has to actually add the 2's to make them a "4", right? But if they equal a "4" only after they're added, how did they acquire this power if it wasn't logically true in the first place? This is an illustration that logic outside of causality exists (almost exclusively - hence the difference between validity and truth), and that many of these arguments rest upon an incorrect understanding and attribution of causality in places where they were presumed to be done away with.
But let's explore individual verses speaking of God changing His mind anyway. The plain statements of verses like Numbers 23:19 which states that God does not change His mind are not figurative or metaphorical and they are direct theological statements about God. The Bible speaks of actions depicting God as having His mind changed because, while God is not human, in order for His actions and intent to be understood, and this is how theologians like St. Thomas Aquinas understood it - from our point of view.
Here are the verses that clearly state that God does not change His mind and this article supports their theological statement as plain and literal - without metaphorical or poetic usage of words or phrases:
1 Samuel 15:29
We should add a note here that there is one further verse that relates to the theological statements of the above verses, but does not truly belong to them: Ezekiel 24:14. In Ezekiel 24:14, although God will not change His mind there, the situation implies that He would under different circumstances. This is not a contradiction to the theologically true statements in the above four verses as we will see below.
So, here are the verses that some might cite as contradicting the Christian theology of the immutability of God's will, but as we examine each by itself below, we show that it is merely a misunderstanding of the context and meaning of the description which is written in a way for us to understand God's will:
Genesis 6:6 - Our premises above supports the suggestion that this verse (and the others) should be interpreted as God having decided to destroy humans, except for Noah and his family, due to humanity's sins. This is because God detested the sins committed. So with these observations, one could describe God as regretting having created humanity - who wouldn't? If your sons or daughters were murderers and thieves and who knows what else, you would certainly have similar feelings. And all the verse means is that God detested their sins - not that He said to Himself, "Shoot, I shouldn't have made them, I thought this might happen."
Genesis 18:22-33 - Here we have Abraham pleading with God to spare Sodom if he could find a number of righteous people which goes from 50 down to 10. But God consenting to Abraham's request to not destroy Sodom after Abraham lowers the number of people he would have to find (the number of people is lowered 5 times) is not the same as God changing His mind in the sense that He originally planned to destroy the city if and only if 50 people are found. It's not like God decided, "Ok, Abraham convinced me, it's a good idea that I hadn't considered or thought of before: if there are 50 people I won't destroy Sodom." God simply agreed to Abraham's request and "changed" His mind with respect to Abraham, not Himself: that is, He agreed to Abraham's request and knew long before that Abraham would make this request (6 requests) and that God would agree to them. Furthermore, the whole point is more or less that God would not find even 10 righteous people in Sodom.
Exodus 32:14 - In this verse, God does not go through with the threat of destruction against the sinful Israelites He had just told Moses about. But this does not mean God did not plan or foresee the fact that Moses would request this and for God not to go through with it. It's similar to, if you have a friend, and he insults you in some way, but that friend really likes coming over to your house. So you tell him that he's not going to come over anymore and he apologizes: you planned for your "change of mind" in the first place, which was not really a change of mind but merely a change of circumstance or decision with respect to your friend. Now God, who would know everything, would plan this with 100% foresight and so this is not a real case of God changing His mind.
Numbers 16:19-35 - Here instead of destroying all Israel, Moses requests that only the rebellious Levites be destroyed. God grants this request, and so this is not a change of mind any more than the example of Exodus 32:14 where you stop inviting a friend from coming to your house because he insulted you until he apologizes: Moses interceded for the people in a way, and God, who in His foreknowledge would know this, changed His decision not mind (from since the beginning of time His decision was this and that His mind with respect to man would change).
Deuteronomy 32:36 - Once again we have a situation for which God planned to have his decision changed with respect to man's circumstance here.
Jonah 3:10 - Here we have another situation where God planned to have his decision changed with respect to man's circumstance here: God knew the Ninevites would repent from before the world was made, and although He threatened destruction, knew they would repent (but not without the threat).
1 Samuel 2:30-31 - In this case, God's anger against Eli and his descendants causes Him to revoke Eli and his house's right to minister over Israel. This is not a change of mind of God, but a change of decision with respect to man.
1 Samuel 15:11, 35 - Here, much like in 1 Samuel 2:30-31 where Eli is reproached, Saul is rejected as king. God knew this would happen, but he appointed Saul until his time to be rejected came, which was due to his incomplete destruction of the Amalekites as commanded. If God ultimately knew this would happen but "changed" His mind with respect to Saul, this is in no way God changed His mind, but only His direction as to who should be king. The fact that God "regretted" making Saul king is an expression for us to understand that God was saddened by Saul not following His will.
2 Samuel 24:16 - Here God does not change His mind. This was merely to serve as an example for the Israelites that God can and will destroy disobedience but spared Jerusalem here because it was dear to Him. But even Jerusalem's sin (under Manasseh) later on would prove too much for God not to punish.
2 Kings 20:1-6 - Here God changes His decision with respect to Hezekiah. With God's foreknowledge He foresaw that Hezekiah would ask Him to recover his health, so God changes the way things work with respect to Hezekiah, not Himself or His will or mind.
1 Chronicles 21:15 - This is the same narrative as 2 Samuel 24:16, so see 2 Samuel 24:16 above. God's decision changed with respect to the Israelites in order to teach them a lesson.
Isaiah 38:1-5 - This is the same narrative as 2 Kings 20:1-6, so see 2 Kings 20:1-6 above. Hezekiah request to not die just yet and God granted this request. God's direction to not end Hezekiah's life was only changed with respect to Hezekiah since God, Who is omniscient, would have foreseen Hezekiah's request and have decided long before anything to not kill Hezekiah but only inform Hezekiah of His intention to do so at that moment.
Jeremiah 15:6 - This decision to punish the Israelites in accordance with their sins would have long been known by God, and He is only changing His action with respect to Himself, but not His mind, which is only changed with respect to the Israelites - God has endured their sins, but no longer.
Jeremiah 18:8 - Again, here God is stating that He will not go through with punishing a nation if it changes and will punish a nation if it strays and starts doing evil. Thus, this is with respect to the change of the nation, not God, who would have foreseen whether a nation/people would repent or not, just like He knew this in the case of Jonah.
Jeremiah 26:3, 13 - Just like the case in Jeremiah 18:8 above, here God changes the course of action with respect to whether the people change or not. God would have foreknowledge as to whether a certain people or not, and this only serves as a warning - one that would be heeded by some but not by others, and God would know who. Why God issues warnings if He knows who would repent and who wouldn't has a two-part explanation: first, it is because of these warnings (pronounced in real life by Jeremiah) that the people repented. Second, this is the method God chose to have the remnant few who are going to stop their sins to repent.
Jeremiah 26:19 - Here Jeremiah explains to the wicked king of Judea, king Jehoiakim, that in the same way when the prophet Micah told Hezekiah that Jerusalem was to be destroyed, Hezekiah did not execute Micah but repented, so should Jehoiakim and Jerusalem change their ways so as not to heap the destruction that would otherwise not happen as it was avoided by Hezekiah. So God did not change His mind: He simply changed the course of events in accordance with the people's actions in the case of Hezekiah.
Jeremiah 42:10 - This verse is a little ambiguous in its meaning. On the one hand, Jeremiah could be saying that God has stopped the disaster-like things that befell these Israelites under the hand of Ishmael son of Nethaniah (Jeremiah 41), or it could be that disasters from the Babylonians or a punishment in the form of a Babylonian retribution for the assassination of their governor at Mizpah originally planned are now not to happen. Either way, there is no "change of mind" on the part of God since He is acting with respect to the character and decisions of the people and had foreknowledge for all of this to happen - whether He would stop a disaster or not - for the people's sins to end. God would not bring disaster now in order, ultimately, for their repentance.
However, should they choose to go to Egypt, they will suffer the very things they left in order to avoid. And this is simply the situation's outcome God decided, not a change in mind.
Amos 7:3,6 - God's judgment here is averted by the plea of Amos. These two situations, Amos 7:1-3 and 7:4-6, are not examples of God changing His mind, but His plan ultimately was to have Amos ask for forgiveness, whether to introduce repentance through Amos to Israel, or perhaps for some other reason we don't know.
Ezekiel 24:14 - Although God does not "relent" from the disaster He has planned here, the text implies God's ability to change His decisions like he does in many of the above verses. But for God to truly change His mind means that He did not know something would happen, which we know is not true in the case of the biblical God, thus He plans in advance when a course of action He would take will not be taken due to the actions of the people, such as bringing peace when disaster is told will befall them if they don't repent, and bringing disaster to wicked people during times of peace. This is not a change of mind: God would indeed punish sin, unless there is a change, which is not a change in God's mind, but the mind of the people, through repentance.
God's mind isn't something that there should be some kind of power over in any real sense, so if one considers God's "inability" to change Himself/His mind as a contradiction of His omnipotence, then this logic works for them. I personally do not agree.