The Bible teaches that God can’t make mistakes or change His mind because He is perfect, all-knowing, all-powerful, unchanging, and His will is eternal.
God can’t make mistakes because He is perfect in all of His ways. There are many Bible verses that state that God is perfect. Psalm 18:30 says “This God—His way is perfect; the word of the Lord proves true; He is a shield for all those who take refuge in Him.” Moses writes in Deuteronomy 32:4 that “The Rock, His work is perfect, for all His ways are justice.” Jesus taught that God is perfect in the Sermon on the Mount—“You therefore must be perfect, as your heavenly Father is perfect” (Matthew 5:48). Since everything God does is perfect, He can’t make a mistake, because a mistake would be an imperfection.
Another reason that God can’t make mistakes is because He is all-knowing and all-powerful. The Bible tells us in many passages that God is all-knowing: “Great is our Lord, abundant in power; His understanding is beyond measure” (Psalm 147:5); “God is greater than our heart, and He knows everything” (1 John 3:20); “Oh, the depths of the riches and wisdom and knowledge of God! How unsearchable are His judgments and how inscrutable His ways!” (Romans 11:33); “And no creature is hidden from His sight, but all are naked and exposed to the eyes of Him to whom we must give an account” (Hebrews 4:13). God is also all-powerful: “Great is our Lord, abundant in power” (Psalm 147:5); “Our God is in the heavens; He does all that He pleases” (Psalm 115:3); “The Lord is slow to anger and great in power” (Nahum 1:3). Paul writes that God “works all things according to the counsel of His will” (Ephesians 1:11). Jesus said “‘What is impossible with man is possible with God’” (Luke 18:27). These passages, and many others, show us that God is all-knowing and all-powerful. If God is all-knowing and all-powerful, then He can’t make mistakes. When someone makes a mistake, it is because he is either unaware of something (a current situation, something that will happen in the future, etc.) or unable to do something he wills. For example, a waiter makes a mistake when he tries to bring a tray of food out to hungry customers but drops the tray on the way. In this case, the waiter wanted to bring the food out but was unable to successfully balance the tray all the way to the table. But God clearly can’t fail to do something He wills, because He is all-powerful. He also can’t be unaware of something, because He is all-knowing. So, because God is all-knowing and all-powerful, He can’t make mistakes.
In addition to not being able to make mistakes, God can’t change His mind either. Numbers 23:19 says “God is not man, that He should lie, or a son of man, that He should change His mind.” God, speaking through Malachi, says “For I the Lord do not change; therefore you, O children of Jacob, are not consumed” (Malachi 3:6). James writes, “Every good gift and every perfect gift is from above, coming down from the Father of lights with whom there is no variation or shadow due to change” (James 1:17). Hebrews 13:8 says of Jesus, who is God, “Jesus Christ is the same yesterday and today and forever.” So if God doesn’t change in any other way, then we can be sure He doesn’t change His mind either.
Another reason that God can’t change His mind is because His will is timeless, or eternal. The Bible teaches that God is eternal and everlasting, and that what He wills, He wills eternally. “The eternal God is your dwelling place, and underneath are the everlasting arms” (Deuteronomy 33:27). “Before the mountains were brought forth, or ever you had formed the earth and the world, from everlasting to everlasting You are God” (Psalm 90:2). Several verses in the New Testament make clear that God is eternal because He is the Creator of time: “but in these last days He has spoken to us by his Son, whom He appointed the heir of all things, through whom also He created the world [lit. the ages]” (Hebrews 1:2); “to the only God, our Savior, through Jesus Christ our Lord, be glory, majesty, dominion, and authority, before all time and now and forever. Amen” (Jude 25); “To the King of the ages, immortal, invisible, the only God, be honor and glory forever and ever. Amen” (1 Timothy 1:17). These passages in the Bible show that God created time and has sovereignty over it. Many verses in the Bible teach that God’s will is eternal: “This was according to the eternal purpose that He has realized in Christ Jesus our Lord” (Ephesians 3:11); “I am God, and there is none like Me, declaring the end from the beginning and from ancient times things not yet done” (Isaiah 46:9-10); “I am the Lord. I have spoken; it shall come to pass; I will do it” (Ezekiel 24:14). Because God is eternal, everything that He wills must have been willed from eternity past. If God has willed everything from eternity, then God’s will is unchanging and He cannot change His mind.
Now that we’ve seen what the Bible teaches on this topic, let’s take a look at two questions that are sometimes asked about God’s unchanging mind.
“If God wills that different things happen at different times, doesn’t this mean that God changes His mind?” It is true that God wills that different things happen at different times, but that doesn’t mean that He changes His mind. It is possible for God to will that things change without changing His will. We do this all the time. For example, someone may will to live in an apartment for two years, fully intending to move into a house afterwards. At the end of the two years, when he moves from the apartment to the house, his will has not changed. Instead, he willed the change from the beginning. In the same way, God can will that changes happen without changes in His will.
Another question that often comes up is: “What about verses that speak of God regretting, repenting, or relenting (e.g., Genesis 6:6; 1 Samuel 15:35; Exodus 32:14)? Don’t these verses mean that God changes His mind?” These verses should be understood metaphorically. Metaphors are used in the Bible to say things about God or about His actions that are true but are described in poetic ways that should not be taken literally. One type of metaphor that the Bible uses is called an anthropomorphism. An anthropomorphism is a metaphor that describes God using words that usually describe human beings because it is easier for humans to understand. For example, there are many verses that speak of God having body parts (e.g., Exodus 7:5, Numbers 6:25, and Psalm 34:15). Whenever the Bible attributes human characteristics to God, these verses should be interpreted metaphorically. So when the Bible speaks of God repenting, etc., we shouldn’t take this to mean that God changes His mind. Rather, we should understand these passages as metaphorically describing a change in God’s actions over His creation. In fact, 1 Samuel 15:29 says “the Glory of Israel will not lie or have regret, for He is not a man, that He should have regret.” So, for example, in Genesis 6:6 God is said to regret only by comparison to humans who are filled with regret. Humans who regret what they have done destroy their work, so God is described as regretting because He destroyed the wicked on the earth through the flood.
In conclusion, the Bible teaches that God can’t make mistakes because He is perfect, all-knowing, and all-powerful, and that He can’t change His mind because He is unchanging and eternal.
(All Bible quotes taken from the English Standard Version unless otherwise noted.)
Those who would like to read more on this topic are encouraged to check out:
GotQuestions.org - Does God Make Mistakes? (http://www.gotquestions.org/does-God-make-mistakes.html)
GotQuestions.org - Can God Change His Mind? (http://www.gotquestions.org/God-change-mind.html)
CARM.org - Can God Change His Mind? (https://carm.org/can-god-change-his-mind)
CARM.org - Anthropomorphisms. (https://carm.org/anthropomorphism-god-relates-us-human-terms)
Norm Geisler - Systematic Theology, Vol. 2: God/Creation (http://amzn.com/0764225529)