“The God of the New Testament is different from the God of the Old Testament.”

Have you heard that idea before from unbelievers? Do you hold to that idea yourself?  The idea asserts God changed somehow between the Old Testament and the New Testament times. They see a difference in God in the 400 years between the testaments. The God of the Old Testament is apparently too harsh, where the God of the New Testament is all about grace.

Here’s the problem. Either they believe there are two different Gods, or they don’t understand that God does not change. The doctrine that God does not change is called divine immutability.

Divine immutability: “By his immutability we mean that it follows from the infinite perfection of God; that he can not be changed by any thing from without himself; and that he will not change from any principle within himself. That as to his essence, his will, and his states of existence, he is the same from eternity to eternity.” Archibald Alexander Hodge, Outlines of Theology: Rewritten and Enlarged (New York: Hodder & Stoughton, 1878), 143.

How can we say God does not change? Recall last week we discussed God’s aseity. That is, his self-existence. If he is self-existent, then he is not caused by creation, but instead has caused creation to be. He cannot be changed by his creation. Look above to old man Hodge’s further clarification. Not only will he not be changed by anything outside of himself, he will not change from any principle inside himself.

“Hold up,” you might say, “I get that he can’t be changed by creation but why can’t he change himself?”

Good question. This gets at the heart of what it is to be God. God is, among many things, perfect. We polish a mirror and call it perfect. We eat a really good meal and call it perfect. We have perfect games in baseball, perfect frames in bowling, and perfect 10’s in Olympic diving. We use perfect as a relative word. That is, “perfect” can be different things for different folks at the same time. God, however, is absolutely perfect.

He is perfect in: his being, his actions, his will, his goodness, his love, his justice, and his wrath. He cannot get any better than he is because if he changes, he is not perfect. The need to change means there is a deficiency in who he is which cannot fulfill his will. We change and react because we do not have total knowledge or total power. If we were omniscient, we would not react as we would already know what will happen. If we were omnipotent, we would not change to accomplish something as the power to accomplish it would already be in us.

God says in the Old Testament that he does not change: “For I the Lord do not change; therefore you, O children of Jacob, are not consumed.” (Malachi 3:6)

God says in the New Testament that he does not change: “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)

“Okay. I guess. But! What about the incarnation?”

The incarnation was the plan from eternity past and not a reaction to the unforeseen consequences of sin. Sin did not cause a “holy huddle” where the trinity met in anguish to figure out what they ought to do next. The Son’s incarnation was the plan from the beginning. By beginning, I mean before creation. There is no change in God, and no surprise in him. Why else did he tell Moses his name is, “I AM WHO I AM.” (Exodus 3:14) He disclosed to Moses his unchanging eternal nature. He disclosed his deity.

Just the same, Peter tells us God, the Rock of Ages, Eternal One, sent his Son to be our passover lamb. He did not do this as a reaction to a crisis, but as a plan made before the foundation of the world and manifested visibly and effectually now for the sake of those who are believers in God. God doesn’t change. It may appears that he does as he revealed more and more of himself to us as time went on until we reached the point of it all; Jesus Christ. He progressively revealed himself throughout the Bible. This is not change, this is the ushering in of glory upon glory.

“And if you call on him as Father who judges impartially according to each one’s deeds, conduct yourselves with fear throughout the time of your exile, knowing that you were ransomed from the futile ways inherited from your forefathers, not with perishable things such as silver or gold, but with the precious blood of Christ, like that of a lamb without blemish or spot. He was foreknown before the foundation of the world but was made manifest in the last times for the sake of you who through him are believers in God, who raised him from the dead and gave him glory, so that your faith and hope are in God.” (1 Peter 1:17–21)