“Though it is only a man’s covenant, yet if it is confirmed, no one annuls or adds to it.” —Galatians 3:15

It is always amazing how God reveals truths to us. It might occur through hearing a sermon, reading an article, or just having a conversation, and something new—to us—opens our eyes. Sometimes God teaches softly, like a gentle whisper, and other times, it feels like a thunderbolt that shakes us to the core.

While studying the epistles of Paul, one of those “lightning bolt” moments struck me. I knew God was showing me something vital, though I did not understand it fully at first. I was studying Galatians, where Paul talks about God’s promise to Abraham, saying it cannot be changed, dissolved, or added to. What exactly does that mean for Christians?

God’s Promise to Abraham

Paul writes about this unchangeable promise in Galatians 3:15-16:

Brethren, I speak in the manner of men: Though it is only a man’s covenant, yet if it is confirmed, no one annuls or adds to it. Now to Abraham and his Seed were the promises made. He does not say, “And to seeds,” as of many, but as of one, “And to your Seed,” who is Christ.

The apostle points us back to the promise God made to Abram in Genesis 12:1, where He says to him, “Get out of your country, from your family and from your father’s house, to a land that I will show you.” Then, in verse 3, He continues, “And in you all the families of the earth shall be blessed.”

A bit later, in Genesis 15:7-8, Abram asks about God’s promise:

Then He said to him, “I am the LORD, who brought you out of Ur of the Chaldeans, to give you this land to inherit it.” And he said, “Lord GOD, how shall I know that I will inherit it?”

To answer his question, God tells Abram to prepare a sacrifice. Abram cuts the animals in two and lays the pieces opposite each other. This covenant procedure was a well-known custom of the time. Both parties would walk between the pieces to show they were bound by the agreement.

But in Genesis 15, Abram never walks through. Only God passes between the pieces, appearing as a smoking furnace and a burning lamp. God was showing Abram—and us, His elect—that this covenant did not depend on Abram at all. Abram had nothing to sign.

The takeaway from all this is that God Himself guaranteed the promise. He concludes it in verse 18:

On the same day the LORD made a covenant with Abram, saying: “To your descendants I have given this land, from the river of Egypt to the great river, the River Euphrates.”

So, this covenant is where God’s purpose takes off—with one man, one promise, and a plan designed to reach the entire world.

Did God Fail in His Promise?

Recall that Galatians 3:15 says that once a covenant is confirmed, it cannot be changed later. Even in our modern world, once a contract is signed, one party cannot scribble in extra terms afterward. If this is true for man’s legal contracts, would not the same apply when God seals a covenant?

This covenant had nothing to do with what Abram did. Remember, it was a one-sided promise sealed by God, which is why it could never be amended nor added to.

Notice that the promise included both a physical and a spiritual aspect. Physically, God promised Abram land, the Promised Land, Canaan. In Genesis 13:15, God says, “. . . for all the land which you see I give to you and your descendants forever.”

Spiritually, the blessing would extend to all nations on earth. God, considering Abram’s change in thinking and behavior, determines he is converted and changes his name to Abraham. Then, He says in Genesis 17:7, “And I will establish My covenant between Me and you and your descendants after you in their generations, for an everlasting covenant.”

The key word is “everlasting.” The question arises: How could Abraham and his descendants possess something forever if they died long ago? If so, did God fail in His promise?

Hebrews 11:39 tells us that all heroes of faith, including Abraham, died without receiving the promise. The only way this covenant can be fulfilled is for Abraham to live again somehow. The only means to live again is through resurrection. It takes little effort to see that eternal life is built right into the promise!

God revealed the very heart of the gospel, the good news of the Kingdom of God, two millennia before Christ was born. Abraham believed God would honor His promise, and that belief, his faith, was accounted to him as righteousness (Romans 4:3, 16-22). We are called to have the same faith.

The Law Could Not Abolish the Promise

Now, God did not make this promise just once, but repeated and expanded the promise repeatedly. In Genesis 26:3-4, God tells Isaac:

I will perform the oath which I swore to Abraham your father. . . . I will give to your descendants all these lands; and in your seed all the nations of the earth shall be blessed.

In Genesis 28:13, He says to Jacob, “I am the LORD God of Abraham your father and the God of Isaac; the land on which you lie I will give to you and your descendants.” He repeats this promise in Genesis 35:11:

I am God Almighty. Be fruitful and multiply; a nation and a company of nations shall proceed from you, and kings shall come from your body. The land which I gave Abraham and Isaac I give to you; and to your descendants after you I give this land.

Each time, the promise expands: more descendants, more nations, more spiritual depth. By the time Christ arrives on the scene, some of Abraham’s descendants carried that promise deep in their identity. Sadly, it blinded them to the much greater, spiritual teaching that He brought. The real promise was never just about land. Its core was always about an everlasting relationship with God.

Paul writes in Galatians 3:17:

And this I say, that the law, which was four hundred and thirty years later, cannot annul the covenant that was confirmed before by God in Christ, that it should make the promise of no effect.

In other words, the law did not—could not—replace the promise. Remember, once God confirms something, binding it with His personal guarantee, it remains confirmed. Paul explains in verse 19 that God added the law to the Old Covenant given at Mount Sinai “because of transgressions,”to show what sin is and to guide people in His way of life until Christ came to live it perfectly.

The important part is to realize that the promise came well before the law. God’s promise is the foundation of the covenant, so nothing could be added to it. The law added to the Old Covenant simply built on what already existed.

Consider Genesis 26:3, 5: “I will perform the oath which I swore to Abraham your father . . . because Abraham obeyed My voice and kept My charge, My commandments, My statutes, and My laws.” This passage verifies that God’s law existed long before Sinai. Genesis 7:2, which addresses clean and unclean animals, shows that Noah knew of these categories, which had existed from creation. Abel’s offering in Genesis 4 suggests that mankind’s first family knew what sacrifices God would accept.

The principles in the law given at Sinai were not new; God had revealed them to people from the beginning. Thus, the law could be included in the Old Covenant, but it was not exclusive to it. Obedience to God’s laws was always part of His relationship with His people.

Where Does the Law Fit?

When God gave His law to Israel, He was not dealing with just one faithful man like Abraham or Noah but with millions of unconverted people. So, as a good and faithful Ruler, He added something extra to help them. Along with the Ten Commandments, His eternal spiritual law, He instituted civil and sacrificial laws to guide their daily lives.

Like God’s promise to Abram, the Old Covenant had both spiritual and physical elements. The spiritual part, the Ten Commandments, was eternal. The physical part included the Levitical priesthood, sacrifices and rituals, and civil rules governing community life. When Christ died, nullifying that covenant, the physical parts became obsolete, but the spiritual law—which existed well before that covenant’s ratification—remains.

In addition, Christ fulfilled everything those old ritual laws pointed to. He became both the High Priest and the perfect Sacrifice for sin. And now, under the New Covenant, God’s Spirit writes His law in our hearts (Jeremiah 31:33; Hebrews 8:10; 10:16).

Thus, Christians have no need for animal sacrifices or an earthly priesthood anymore. They live by following His spiritual law, which Christ summarized as loving God and loving our neighbor (Matthew 22:37-40), just as He intended from the beginning.

Grafted Into the Promise

We need to return to Galatians 3:16, where Paul writes:

Now to Abraham and his Seed were the promises made. He does not say, “And to seeds,” as of many, but as of one, “And to your Seed,” who is Christ.

Understanding this point is critical to grasping the entire plan of God. The original promise was made directly to Jesus Christ! He is the true Heir, the one Seed, the one who brings the entire plan together.

Hebrews 9:15 teaches, “He is the Mediator of the new covenant . . . that those who are called may receive the promise of the eternal inheritance.”

Here is the big thunderbolt, which even many learned theologians do not understand: The covenant made to Abraham and the New Covenant in Christ are one continuous promise. Jesus did not come to change the promise but to confirm it. He was the first to receive that eternal inheritance as the Firstborn (see Romans 8:29; Colossians 1:18; Revelation 1:5).

This concept now becomes very real for God’s elect. Paul writes in Galatians 3:29, “And if you are Christ’s, then you are Abraham’s seed, and heirs according to the promise.” So, when a person repents, is baptized, and receives God’s Spirit, he or she becomes grafted into the same unchangeable promise God made to Abraham.

Romans 8:16-17 declares, “The Spirit Himself bears witness with our spirit that we are children of God, and if children, then heirs—heirs of God and joint heirs with Christ.” The eternal inheritance promised to Abraham, confirmed through Christ, now belongs to us through faith.

God’s purpose has never been about law-keeping to attain salvation but about believing God, just as Abraham did. This dedicated belief leads to obedience—for, as we know, faith without works is dead (James 2:14-26)—but the foundation has always been faith in God’s promise.

The apostle John records in Revelation 21:7, “He who overcomes shall inherit all things, and I will be his God and he shall be My son.” This verse spells out the ultimate fulfillment of the promise that began with Abraham. Jesus Christ confirmed it through His sacrificial work, and it will be complete for God’s elect when God establishes His Kingdom on earth at Christ’s return.

That will be when the unchangeable promise becomes eternal reality. This truth is the gospel—the Good News—Christ came to deliver (Mark 1:14-15). If we repent and believe the gospel, the same promise of eternal inheritance belongs to us, just as Abraham believed God, and it was accounted to him for righteousness.

Hold On to the Promise

God recognized Abraham’s desire for a relationship by his willingness to conform to God’s way of life. He explicitly obeyed. He desired to be in a right and close relationship with God. Thus, Paul calls Abraham “the father of us all” (Romans 4:16). He modeled in his life what God looks for in a relationship.

Further, if someone truly believes God, he will automatically live a different way than the rest of the world. Belief transforms life; faith produces obedience. If we fail to believe and respond with obedience and growth in Christ’s image, rejecting God and His covenant, we can lose what He has offered (Hebrews 6:4-8; 10:26-31).

When we believe God through Christ, the same promise applies to us, which is why it is an unchangeable promise: It was never based on what a man could do, but on what God has already done.

The world changes. People break promises. False traditions twist the truth. But God’s promise stands unbroken.

The real question to ask ourselves is: “Am I part of that promise?” If we belong to Christ, that inheritance is ours. Eternal life is ours.

Our hope does not depend on how perfectly we perform (though we should strive to please God as Abraham did) but on how faithful God is in keeping His Word. As Paul tells us in I Corinthians 1:9, “God is faithful, by whom you were called into the fellowship of His Son, Jesus Christ.” The same God who said to Abraham, “I will bless you,” is saying to us, “I will give you eternal life.”

We must hold on to the promise and live every day believing it with all our hearts. Everything else in this world may fade, but the promise of God never will. One day, just like Abraham and all the heroes of faith, we will stand in the reality of that promise by the power of the God who swore by Himself.

Then we will fully understand what we have only believed and seen by faith—that His Word is sure, His covenant is forever, and His unchangeable promise was worth trusting all along.