This attribute of God is sometimes called constancy. God is devoid of change with regard to His attributes or promises. Note that this doesn’t imply that God never does or says anything different, or that his feelings don’t change, since he is emotional. Only his attributes and promises are unchanging (Heb. 13:8; Jas. 1:17; 1 Sam. 15:29). Several passages teach the immutability of God:
(1 Sam. 15:29) “Also the Glory of Israel will not lie or change His mind; for He is not a man that He should change His mind.”
(Mal. 3:6) For I, the LORD, do not change; therefore you, O sons of Jacob, are not consumed.
(Ps. 33:11) The counsel of the Lord stands forever, the plans of His heart from generation to generation.
(Jas. 1:17) Coming down from the Father of lights, with whom there is no variation or shifting shadow.
(Num. 23:19) God is not a man, that He should lie, nor a son of man, that He should repent; has He said, and will He not do it? Or has He spoken, and will He not make it good?
(Heb. 6:17) In the same way God, desiring even more to show to the heirs of the promise the unchangeableness of His purpose, interposed with an oath.
(Heb. 13:8) Jesus Christ is the same yesterday and today and forever.
What about times in the Bible where God seems to change his mind? (Ex. 32:11-14)
See comments on Exodus 32:11-14.
The immutability of God produces a number of consolations to the believer:
God’s promises are true regardless of my feelings. God works independently of our feelings or intuition. Whether I am on my best day or my worst, God’s promises don’t change.
God is constant and not capricious. He doesn’t change—even if life and circumstances do. He is dependable and a sturdy foundation for life. Everything good about God could someday change if it weren’t for this attribute.