Unpacking Galatians 4:23: Born Through Promise

Children of Flesh or Promise: The Heart of Paul’s Argument

To grasp Galatians 4:23, we need to step into the urgent world Paul was writing to - a world where new believers were being told they had to follow Jewish laws to truly belong to God.

Paul wrote to churches in Galatia made up of both Jewish and Gentile believers, and some teachers had come in insisting that faith in Jesus wasn’t enough - people also had to be circumcised and keep the Old Testament law to be saved. This turned grace into a performance, making salvation something earned rather than given. So Paul goes back to Abraham’s story to show there have always been two ways of living: one based on human effort, the other on God’s promise. He presents Hagar and Sarah as symbols of two covenants: the Mount Sinai covenant that leads to slavery, and the heavenly covenant that brings freedom.

In Galatians 4:23, when Paul says, 'But the son of the slave was born according to the flesh, while the son of the free woman was born through promise,' he’s contrasting Ishmael, born through human planning when Sarah told Abraham to sleep with her servant Hagar, with Isaac, born miraculously to elderly parents because God had promised it. Here, "the flesh" refers to human effort, strategy, and attempts to impose our terms on God’s plan, not merely the physical body. The promise points to God’s power to do what seems impossible, relying only on His word and timing. This is not merely ancient history. Paul says it illustrates how we relate to God today.

Later, in Galatians 4:26, Paul makes it personal: 'But the Jerusalem above is free, and she is our mother.' He’s saying we don’t belong to the old system of rules and striving - we are children of the free woman, born not by what we do, but by what God has promised. This shifts everything: our standing before God depends not on how well we keep laws, but on whether we trust His promise, as Abraham did.

Born by Flesh or Promise: Two Ways of Living

At the heart of Galatians 4:23 is a divine contrast: one son born by human effort, the other by God’s promise - setting up a lasting picture of two ways to live before God.

Paul presents the story of Ishmael and Isaac as a symbolic lesson, an allegory in Galatians 4:24, rather than merely history. He writes, 'Now this may be interpreted allegorically: these women are two covenants.' Hagar, the slave woman, represents the old covenant from Mount Sinai, which leads to slavery because it depends on human effort to keep the law. Sarah, the free woman, represents the new covenant, which comes from God’s promise and brings freedom. This is not about biology. It concerns how we attain right standing with God - by trusting Him rather than trying harder.

When Paul says Ishmael was 'born according to the flesh' (Greek: *kata sarka*), he’s talking about human effort - Abraham and Sarah trying to fulfill God’s promise in their own timing and way, by having Abraham sleep with Hagar (Genesis 16:15). But Isaac was 'born through promise' (Greek: *dia epaggelias*), because his birth came from God’s word alone, even though Sarah was past childbearing age (Genesis 21:1-2; Romans 9:9). The phrase 'according to the flesh' refers not merely to physical birth, but to living based on what we can control, see, or achieve. 'Through promise' means living by faith in what God said He will do, even when it seems impossible.

This contrast between law and grace is central to Paul’s message. The law, like Hagar, leads to slavery because it depends on what we do. But the promise, like Sarah, brings freedom because it depends on what God has done. Paul wants the Galatians to see that adding rules to faith in Jesus is like going back to Hagar - it turns grace into a test we have to pass. Instead, we are called to live like Isaac, children of the promise, born not by human effort but by God’s faithful word.

Children of the Promise: Our True Identity in Christ

Paul’s message in Galatians 4:23 concerns not merely two sons of the past, but who we truly are today as followers of Jesus.

Paul wants us to understand that being a Christian does not involve joining a religious system or earning favor through rules. It is about being reborn into a new family. We are not children of the slave woman, born through human effort, but children of the free woman, born through God’s promise. This is exactly what John means in John 1:13 when he says, 'who were born, not of blood nor of the will of the flesh nor of the will of man, but of God' - our new life comes from God’s action, not ours.

And this new birth changes everything. As Paul says in Romans 8:15, 'You did not receive the spirit of slavery to fall back into fear, but you have received the Spirit of adoption as sons, by whom we cry, “Abba! Father!”' We’re no longer slaves trying to earn our way in, but sons and daughters welcomed into God’s family by grace. This is the freedom Paul talks about - freedom not just from the law’s demands, but into the joy of being loved as children. Our identity isn’t built on how well we perform, but on the promise God made and kept in Jesus. That’s why Paul can say in Galatians 4:26, 'But the Jerusalem above is free, and she is our mother' - we belong to a new city, a new covenant, a new way of life.

So the good news is this: we don’t have to strive to be accepted. We are already accepted, not because of what we’ve done, but because of what God has promised and fulfilled. This truth frees us to live not by fear or rules, but by faith and love - the very heartbeat of life in the Spirit.

Promise and Flesh Across the Story of Scripture

The contrast between being born according to the flesh or through promise is not merely a moment in Galatians; it is a thread that runs through the entire Bible, shaping God’s story of redemption.

Back in Genesis 15:4-5, God told Abraham, 'This man will not be your heir; no, the one who will come from your own body will be your heir.' He then took him outside and said, 'Look at the sky and count the stars - if indeed you can count them.' Then he said to him, 'So shall your offspring be.' That promise, not human strategy, became the foundation of God’s plan.

Later, in Romans 9:6-8, Paul clarifies, 'It is not as though God’s word did not stand. For not all who are descended from Israel are Israel... nor are children by physical descent. No, the children of the promise are counted as the true offspring.' This means belonging to God has never depended on bloodline or effort, but on receiving His promise by faith, as Isaac did.

Even in John 8:33-35, when religious leaders claimed, 'We are Abraham’s descendants and have never been slaves to anyone,' Jesus responded, 'I tell you the truth, everyone who sins is a slave to sin... So if the Son sets you free, you will be free indeed.' True freedom doesn’t come from heritage or law-keeping - it comes through the promise fulfilled in Christ, who breaks the chain of spiritual slavery.

This same contrast echoes in Hebrews 12:18-24, where Mount Sinai - symbolizing the law, fear, and flesh - stands against Mount Zion, the heavenly Jerusalem, where we come 'to the city of the living God' and 'to Jesus the mediator of a new covenant.' We do not live under the shadow of rules and threats. We live in the light of promise, where grace gives us boldness to draw near. That truth should shape how we live every day - not striving, but trusting, and how churches gather - not as performance clubs, but as family, welcoming all who call Jesus Lord.

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