If you perform a cursory review of scripture, you might come to the conclusion that the God of the Old Testament and the God of the New Testament are two very different beings. In fact, this is a point often cited by critics of Christianity.
Yet Christians repeatedly claim that God does not change. Are they right? Is God unchanging? And does the Bible support this idea?
God is unchanging, infinite, and perfect. His nature is immutable, but He presents Himself throughout scripture in different ways at different times for different purposes.
Why People Think God Can Change
The Old Testament certainly contains significant warfare, conquest, and other large-scale displays of calamity. The New Testament, by contrast, depicts Jesus as a bringer of peace who calls his disciples to live with love and grace toward others.
So What Really Changed?
If God is unchanging, why does the Old Testament look so different from the New Testament?
The difference between the two is related to man’s sin, and God’s solution to sin. From the call of Abraham in Genesis 12 onward, the Old Testament describes how God prepared the people of Israel—and ultimately the world—to receive Jesus.
As God’s plan unfolded, He displayed power and glory as He established Israel as His people. He provided Israel deliverance from slavery in Egypt and victory over other nations in the conquest of Canaan.
As the Old Testament continued, Israel went through patterns of rebellion and turning away from God. For every king that led the people faithfully, three others led them astray. This pattern of rebellion resulted in cycles of strife and judgment. Israel frequently brought war upon themselves through unholy alliances and improper worship, and God continuously answered with corrective action.
Yet even when God judged Israel and turned them back to Himself, He did so because of His own unchanging nature:
“I the Lord do not change. So you, the descendants of Jacob, are not destroyed. Ever since the time of your ancestors you have turned away from my decrees and have not kept them. Return to me, and I will return to you,” says the Lord Almighty.
Malachi 3:6-7
When God spoke these words through the prophet Malachi, the people of Judah were still returning to Jerusalem from exile in Babylon. This was the ultimate act of corrective judgment that God carried out on His chosen people in the Old Testament, but still, it was not enough to turn His people away from their sins.
Soon, God’s plan would take a new direction.
Why the Change?
God’s strategy between the Old and New Testaments did not change because He realized that His plan wasn’t working or because He changed His mind and came up with a better strategy.
The plan that we read—including its sudden strategic shift between the Old and New Testaments—had been God’s plan from the start. He first promised deliverance through Jesus at the moment of the fall (Genesis 3:15) and put His plan into motion with the call of Abraham.
Still, we humans needed to see our need for Jesus and we needed to understand our inability to correct our own sins and save ourselves. The story of Israel, with all of its triumphs and failures, reveals this need.
Yet God remained unchanging through it all. Even as He executed judgment, He protected His original plan by preserving His people. Every action He took from the beginning was taken with the end in His sight. As the Psalmist describes:
Lord, you have been our dwelling place
throughout all generations.
Before the mountains were born
or you brought forth the whole world,
from everlasting to everlasting you are God.
You turn people back to dust,
saying, “Return to dust, you mortals.”
A thousand years in your sight
are like a day that has just gone by,
or like a watch in the night.
Psalm 90:1-4
God has been the same throughout the whole unfolding of His plan, even though we experience His plan as a series of successive changes.
Why God’s Immutability Matters
If you have read our piece on evolution, you know that being created in the image of an unchanging God is important for understanding how we relate to Him. Considering change in this manner also helps us to understand how God’s perfection and immutability are interrelated.
When we consider change in evolutionary terms, we understand that change involves the addition and removal, improvement and deterioration.
Since God is perfect, He must be unchanging. And since He is infinite, He must be unchanging.
If God were to change, the inference would be that He was not previously perfect and complete, or that He is no longer perfect and complete.
Further, it is only because God is perfect, infinite, and eternal that His plan for us can work at all. God’s plan is temporal, but His nature is eternal. So His plan serves to create a path for us from the temporal world of sin and death to His eternal kingdom.
Jesus affirmed this relationship between God’s eternal and unchanging glory and His time-based work on earth when he prayed:
After Jesus said this, he looked toward heaven and prayed:
“Father, the hour has come. Glorify your Son, that your Son may glorify you. For you granted him authority over all people that he might give eternal life to all those you have given him. Now this is eternal life: that they know you, the only true God, and Jesus Christ, whom you have sent. I have brought you glory on earth by finishing the work you gave me to do. And now, Father, glorify me in your presence with the glory I had with you before the world began.
John 17:1-5
Jesus’ glory was revealed to us in his life, death, and resurrection. But the glory has always been his since before time began because he is of the same nature as the Father—unchanging, eternal, and divine.
Our Lasting Hope
For you have been born again, not of perishable seed, but of imperishable, through the living and enduring word of God.
1 Peter 1:23
Finally, it is God’s unchanging nature that gives us confidence in His plan and hope for eternity. The new birth that we have received is rooted in God’s unchanging character. It is not subject to death, decay, or revocation.
The Lord continues to be our dwelling place, just as he was the dwelling place that Moses proclaimed in Psalm 90.
So the God that has been revealed to us in scripture and the faith that has been imparted on us through Jesus are all that we need.
Jesus Christ is the same yesterday and today and forever.
Do not be carried away by all kinds of strange teachings.
Hebrews 13:8-9a
