I will sing of the Lord’s great love forever;
with my mouth I will make your faithfulness known
through all generations.
I will declare that your love stands firm forever,
that you have established your faithfulness in heaven itself.
(Psalm 89:1, 2 NIV)

 The Bible often repeats this truth: God’s promises are unfailing; they last forever. God doesn’t change. 

Why do God’s promises never fail? Once we begin to investigate God’s character and nature, we see that God’s promises never fail because God is unchanging. 

What Is God’s Immutability?

We call God’s unchangeableness “immutability.” Immutability means God does not change in his being, purposes, or plans. Before we consider what this practically means for us, let’s establish this truth from God’s Word by looking at one passage from the Old Testament and one from the New. 

In the beginning you laid the foundations of the earth, and the heavens are the work of your hands. They will perish, but you remain; they will all wear out like a garment. Like clothing you will change them and they will be discarded. But you remain the same, and your years will never end. (Psalm 102:25-27 NIV)

Every good and perfect gift is from above, coming down from the Father of the heavenly lights, who does not change like shifting shadows. (James 1:17 NIV)

Both passages establish that God is unlike anything else in all creation. All we see in the world varies and changes, but God remains the same forever. 

Change Implies Imperfection

This makes sense. Nothing in our experience stays the same. Everything created changes. But this is not true of God (since he is uncreated). 

If God were subject to change, that would imply that he could either get worse or better. If he could get worse—heaven forbid!—he could turn back on his promises of salvation for us. And if he could get better, that implies that, at any given moment, he is not as good as he can be. In other words, he would not be God. 

What about When God Seems to Change His Mind?

But what about those situations in the Bible where it appears like God changes his mind? For example, God told Jonah to warn Nineveh that he would destroy the city in forty days (Jonah 3:4). But once the Ninevites repented of their evil ways, God relented and didn’t bring the destruction he threatened. Isn’t this a clear example of God changing his mind? 

We must keep in mind that all of the Bible is inspired by God (2 Timothy 3:16). Prophets like Jonah were only able to speak because God’s Spirit inspired them to do so (2 Peter 1:20-21). Clearly, God is not going to contradict himself. When we have clear Bible passages telling us that God does not change, but we have a story in the Bible where it appears that he does change, we need to interpret those accounts in light of the Bible’s clear teaching. The Bible does not contradict itself because God does not contradict himself. 

So what happened in the case of Nineveh? The prophets give us a clue. God tells Jeremiah his warnings of judgment include the opportunity for his people to repent and God to relent of threatened judgment.  

The instant I speak concerning a nation and concerning a kingdom, to pluck up, to pull down, and to destroy it, if that nation against whom I have spoken turns from its evil, I will relent of the disaster that I thought to bring upon it. (Jeremiah 18:7-8 NKJV) 

God says the same thing in Ezekiel 33:14-16, too. 

It’s not that God changed his mind. How could he? He already knows the beginning from the end (Isaiah 46:10). He is perfect in knowledge and knows everything (Job 36:4). 

Numbers 23:19 (ESV) says, “God is not man, that he should lie, or a son of man, that he should change his mind. Has he said, and will he not do it? Or has he spoken, and will he not fulfill it?” 

We usually change our minds because we learn something not previously known to us. But this is impossible with God because he knows all things (1 John 3:20). 

What About Prayer?

God’s immutability should affect us profoundly—especially in prayer. While it’s popular to believe prayer somehow changes God’s mind, nothing could be further from the truth. God’s Word says, “He who is the Glory of Israel does not lie or change his mind; for he is not a human being, that he should change his mind” (1 Samuel 15:29 NIV). 

It’s better to view our prayers as part of God’s ordained purposes. God commands us to pray so that we can participate in his plans. He already knows what is going to happen. Prayer is not a means by which we change God, but rather a means by which God changes us and our circumstances. 

What Immutability Means for God’s Promises

God’s immutability is the guarantee that whatever he promises will come to pass. For those who have faith in the Son, Jesus, he will surely save us because he too “is the same yesterday and today and forever” (Hebrews 13:8 ESV). For those whom God has promised he will eternally judge—unless they repent—that judgment will surely fall upon them. 

“For I am the Lord, I do not change.” (Malachi 3:6 NKJV)

Find your rest in God’s immutability. Find your peace in God’s unchanging nature.