One of the most reassuring truths of the Christian life is that God can be trusted. One of the most famous verses in the Bible – Psalm 23:1 – demonstrates this: “The Lord is my shepherd; I shall not want.” David has confidence that the Lord will provide for Him because of what he knows to be true: the Lord is a good shepherd who provides for His sheep. But what if it were possible for God to become a bad shepherd or to stop providing for His sheep? How is it that David could have such confidence and that we can echo that confidence? The answer is found in God’s immutability. Put simply: God does not change. We can know certain things about God with absolute certainty because He is the same yesterday, today, and forever – as is His Son, Jesus (Heb. 13:8).
How do we know God is unchanging? We know it the same way we know everything else about Him – because He has told us. Psalm 102:25-27 reminds us that the Lord created the heavens and the earth. Even so, there will come a time when they perish, but even when that day comes, the Lord will still remain. As the psalmist writes, “You will change them like a robe, and they will pass away, but you are the same, and your years have no end” (Ps. 102:26b-27). Even though the earth will change, God is – and will be – the same, because He is unchanging.
But we should take time to consider this a bit more deeply. What does it mean precisely that God never changes? The Bible gets specific about this truth. It means that God’s character never changes. In Malachi 3, God promises His people that He is coming to judge His people. He makes clear that this judgment will result in the destruction of His enemies while also purifying His people. How can the people be certain that God will not sweep the righteous away with the wicked? They can be certain because they know God’s character, and God reminds them: “For I the Lord do not change; therefore you, O children of Jacob, are not consumed” (Mal. 3:6). James also tells us that every good gift comes from Him because He is “the Father of lights with whom there is no variation or shadow due to change” (James 1:17). God is light and has no darkness in Himself (1 John 1:5), and that will never change. He is as He has always been, and He will always be as He is.
The Bible also makes clear that God is unchanging in His plans and purposes. His purposes stand forever, and His plans last from generation to generation (Ps. 33:11). He will accomplish everything He plans (Isa. 46:10), and no one can stop Him (Dan. 4:35). His plan of redemption was put in place before the world was ever created (Eph. 1:4; 1 Pet. 1:20; Rev. 13:8), and nothing can stop it or even hinder it. His plans and purposes never change. Some argue against this point based on certain passages that seem to show God changing His mind (Ex. 32:9-14; Isa. 38:1-6; Jonah 3:4,10) or experiencing sorrow for things (Gen. 6:6; 1 Sam. 15:10). However, these texts simply show us God’s attitude at the exact moment described. They say nothing about whether such “changes of mind” were part of God’s plan all along or not. Based on other texts, we would have to say they were part of His plan – because His plan never changes. God certainly interacts with, and responds to, His creation – especially human beings. But these interactions never change His plans. They are always perfect, and He always carries them out.
The Bible also makes clear that God never changes with regard to His promises. God never lies (1 Sam. 15:29). He never says He will do something and then fails to do it. He never speaks a promise and then fails to keep it (Num. 23:19). His calling – once given – is irrevocable (Rom. 11:29). God always keep His word.
But why do we care? Why does this matter? It matters, first, because it means we can actually know God truly. If it were possible for Him to change, we would have no confidence that what is true of Him today would be true tomorrow. In that case, the One who is holy today could be wicked tomorrow. The One who rewards those who diligently seek Him today (Heb. 11:6) might choose not to reward them tomorrow. If God could change, it would remove all possibility of knowing Him certainly and truly. Thankfully, we can know Him. He has revealed Himself, and we can be sure of His character.
Second, it is important because we can know God’s ultimate purposes and plans. Even though we may not know all the details, we can know God’s purpose in this world. He made this universe for His Son (Col. 1:16) and He is summing up all things in Christ (Eph. 1:10). We know that whoever believes in the Son has life but whoever does not believe will have God’s wrath (John 3:36). The purposes of God are sure. He has made them clear. And since He never changes, we can know they are still in place – even in moments when the opposite may seem true. Has He not said, and will He not do it. Of course He will, because He never changes.
And it matters because God has made promises to us. If God can change, then the promises mean nothing. But God cannot lie, which means His promises – like the promise of eternal life for His people – are certain (Tit. 1:2). It is impossible for God to lie, which means we can hold fast to the hope found in His promises and know that we will not be disappointed (Heb. 6:17-18; Rom. 5:5).
Take some time today to consider that God never changes. Moreover, take some time to consider what it would be like if He could change. Then praise Him that such a terrible thing will never happen. Worship Him as He is – and as He always will be. And hold fast to His promises – which will never prove false.