Lorenzo Palon

Theme Verse: Galatians 4:28
“Now you, brothers and sisters, like Isaac, are children of promise.”

There are passages in Paul that become more difficult the more carefully we read them. Galatians 4:21–31 is one of them. Paul takes the familiar story of Sarah, Hagar, Isaac, and Ishmael and does something astonishing with it. Hagar becomes associated with Mount Sinai, the Mosaic covenant, and “the present Jerusalem,” while Sarah represents freedom, promise, and “the Jerusalem above.”

Read quickly, the passage can sound like Paul is saying something painfully simple: Judaism is slavery, Christianity is freedom, the Old Testament has been replaced, and Christians have taken Israel’s place.

But that is not actually the argument Paul has been making.

To understand Sarah and Hagar in Galatians 4, we have to begin before Paul mentions either woman. His real question is not, “Which religion is better?” His question is much more specific: Who belongs to Abraham’s promised family, and on what basis do they belong?

That question changes everything.

The Argument Begins with Abraham, Not Hagar

Paul’s argument stretches back through Galatians 3. Some teachers were apparently persuading the Gentile believers in Galatia that faith in Christ was not enough to establish their full covenant identity. If these Gentiles really wanted to belong to Abraham’s people, they needed circumcision and incorporation into the Torah-defined covenant community.

Paul responds by going back to Abraham himself.

Abraham received God’s promise before Sinai. Before Moses. This was before the giving of the Torah. Before circumcision could function as a boundary marker that distinguished Israel from the nations, God had promised Abraham that the nations would be blessed through him.

God had promised Abraham that the nations would be blessed through him. Paul believes that this promise has now reached its decisive fulfillment through Israel’s Messiah and the gift of the Spirit.

This explains his remarkable declaration in Galatians 3:29: “If you belong to Christ, then you are Abraham’s offspring, heirs according to the promise.”

Gentile believers do not need to become Jews before they can become Abraham’s children. They belong to Abraham because they belong to Abraham’s Messiah.

The Torah was therefore not God’s failed experiment. It belonged to Israel’s covenant history and had a genuine role within God’s purposes. But Paul refuses to allow the Torah to become the final mechanism by which the nations receive Abraham’s inheritance.

The promise came before Sinai, and it has reached its goal in Christ.

Why Paul Turns the Story Upside Down

This is what makes Paul’s use of Sarah and Hagar so shocking.

His opponents could easily have imagined themselves standing on the Isaac side of Abraham’s family. They possessed circumcision, Torah, Jerusalem, and Israel’s ancestral traditions. Gentile believers, by contrast, might naturally seem like outsiders who needed to enter Israel through those established covenant markers.

Paul reverses the categories.

Hagar, the enslaved woman, becomes associated with Sinai and the present Jerusalem. Sarah, the free woman, is associated with the promise and the Jerusalem above. The Gentile believers whom others apparently wanted to place under Torah are told that they are already “children of promise” like Isaac.

Paul is not attacking Abraham’s family. He is arguing about how Abraham’s family must now be identified after the coming of Christ.

The decisive marker is no longer an ethnic distinction defined by the Torah. It is now defined by belonging to Christ and receiving the Spirit.

This is why Galatians 4 cannot be separated from Galatians 3. Paul has already asked the Galatians how they received the Spirit. Was it through “works of the law,” or through hearing with faith? His answer is obvious. God gave them the Spirit before anyone circumcised them.

Their own Spirit-filled existence therefore testified that God had already welcomed them.

“According to the Flesh” Does Not Mean What We Often Think

Paul says that Ishmael was born “according to the flesh,” while Isaac was born “through promise.”

This language has sometimes been misunderstood as if Paul were contrasting sinful sexuality with some more spiritual kind of birth. But both Ishmael and Isaac were physically conceived. Paul’s contrast lies elsewhere.

Ishmael represents what Abraham’s household could produce through ordinary human arrangements. Isaac represents what only God’s promise could accomplish.

Sarah was barren. Abraham was old. The promised child existed because God remained faithful when ordinary human possibility had reached its limit.

That fits Paul’s argument perfectly.

Earlier he had asked the Galatians, “Having begun by the Spirit, are you now being perfected by the flesh?” Paul is not condemning the physical body. He is exposing the folly of beginning with God’s supernatural gift and then trying to secure covenant status through merely human means.

The contrast is therefore between what humanity can establish and what God’s promise creates.

Christian identity is not something we manufacture through religious badges, ancestry, achievement, or boundary markers. It is received because God has acted in Christ and given his Spirit.

Why Hagar Becomes Mount Sinai

Paul then makes perhaps his strangest move: Hagar represents Mount Sinai.

At first this connection seems almost impossible to understand. Sinai was where God gave Torah to Israel. How can Paul associate that sacred event with an enslaved woman?

The controlling idea is slavery.

Hagar was enslaved. Paul has already used slavery language to describe existence under the guardianship of the law before the coming of Christ. He is now warning Gentile believers that voluntarily placing themselves under the Mosaic covenant as the basis of their identity would mean moving backward in the biblical story.

Paul is not saying Torah was evil.

He is saying that a covenantal arrangement belonging to an earlier stage of salvation history cannot become the final destination now that Messiah has come.

The schoolmaster cannot become the goal of education. The guardian cannot become the permanent condition of the mature heir.

The problem is not Torah itself. The problem is trying to make Torah do, after Christ, what God never intended it finally to do.

The Dangerous Phrase: “The Present Jerusalem”

Paul’s statement that Hagar “corresponds to the present Jerusalem” has produced some terrible interpretations in Christian history.

Some Christian interpreters have reduced the passage to a simplistic formula: Jews belong to Hagar and slavery, while Christians belong to Sarah and freedom. From there it is only a short distance to contempt for Jews and the assumption that Christianity simply replaced Israel.

But Paul’s argument says something far more specific than that.

Paul himself is Jewish. The entire theological world of Paul’s argument is provided by Abraham, Sarah, Isaac, Isaiah, Jerusalem, Israel’s Scriptures, Israel’s promises, and Israel’s Messiah.

This is an argument occurring inside Israel’s story about what Israel’s God has now done through Israel’s Messiah.

Paul’s concern is specifically with making Torah observance necessary for Gentile covenant membership. His polemic is sharp because he believes that requiring circumcision would deny what God has already accomplished through Christ and demonstrated by giving Gentiles the Spirit.

Therefore, “present Jerusalem” should not become a code for despising Jewish people.

Paul is arguing about covenantal location in the unfolding biblical story, not racial or ethnic superiority.

The Forgotten Key Is Isaiah 54

One of the most revealing moments occurs when Paul suddenly quotes Isaiah:

“Rejoice, you barren one who does not bear.”

Why Isaiah 54?

Because Isaiah is speaking about barren Zion.

Jerusalem appeared abandoned and devastated, yet God promised an astonishing restoration. The barren woman would discover that her children were more numerous than she could have imagined.

Paul sees a pattern.

Sarah was barren, but God created a family through promise. Zion appeared barren, but God promised unexpected children. Now, through Messiah and the Spirit, people from the nations are appearing within Abraham’s family.

The apparently impossible promise is coming true.

This is why “the Jerusalem above” is not Paul’s name for an escape from earth into heaven. It represents God’s promised new creation breaking into the present through Christ and the Spirit, where the coming age has already begun to take shape.

The language is eschatological.

The Jerusalem above represents God’s promised new-world reality invading the present. The future restoration promised by the prophets has begun to appear through the Messiah and the Spirit.

The Galatian believers are evidence that new creation has already begun.

They are children whom nobody expected.

Is Paul Allegorizing the Old Testament?

Paul describes the Sarah–Hagar comparison using the Greek verb allēgoreō. That is why many translations call this an “allegory.”

But we should be careful about what we mean.

Paul does not treat Genesis as a collection of secret symbols that allow readers to ignore its historical meaning. He is not claiming that every tent, camel, well, and household servant conceals a hidden Christian doctrine.

The argument of Scripture itself tightly shapes Paul’s reading.

He connects Genesis with Isaiah. He sees Sarah’s barrenness, Isaac’s miraculous birth, Zion’s promised restoration, Abraham’s worldwide family, Christ, and the gift of the Spirit as parts of one unfolding divine story.

That is very different from arbitrary allegorization.

Paul is reading Israel’s Scriptures eschatologically. He believes the promised future has begun and therefore rereads the earlier story from the vantage point of Messiah and the Spirit.

Paul does not discard the Old Testament. Instead, he reads it as an unfolding story whose promised destination has now arrived in Christ.

What About “Cast Out the Slave Woman”?

Paul’s quotation of Sarah’s words from Genesis 21 is perhaps the most uncomfortable part of the passage: “Cast out the slave woman and her son.”

This verse must never become a Christian permission slip for excluding Jews, Muslims, Arabs, women, enslaved people, or anyone else supposedly associated with Hagar.

Genesis itself will not permit that reading.

God sees Hagar in the wilderness, hears Ishmael, rescues them, and gives Ishmael a future. Genesis itself therefore resists any interpretation that treats Hagar and Ishmael as objects of divine contempt. Paul is taking one feature of their story—slavery and inheritance—and using it rhetorically within a specific Galatian controversy.

Some interpreters understand Paul as calling for the removal of the rival teachers. Others understand the quotation primarily as a warning to the Galatians themselves: do not surrender your identity as children of promise by embracing the very covenantal arrangement Paul believes Christ has brought to its intended goal.

Either way, Paul’s point is not hatred.

His concern is inheritance.

The Galatians must not abandon the freedom God has already given them.

The Real Contrast Is Promise and Humanly Secured Status

Galatians 4:21–31 therefore should not be summarized as “Old Testament bad, New Testament good.”

Nor is Paul simply contrasting Judaism with Christianity.

The deeper contrasts are slavery and inheritance, flesh and Spirit, humanly secured status and divine promise, the age awaiting fulfillment and the new age inaugurated in Christ.

That is why the passage really ends at Galatians 5:1:

“For freedom, Christ has set us free.”

But even that freedom can be misunderstood if we do not keep reading.

Paul is not announcing freedom from obedience. By Galatians 5:13, freedom is freedom to serve one another through love. By Galatians 5:16–26, the Christian life becomes life by the Spirit, producing love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, and self-control.

Christian freedom is therefore not autonomy.

It is Spirit-enabled participation in the life of God’s new creation.

We Are Children of Promise

Paul’s Sarah–Hagar comparison ultimately tells us something profound about grace.

God creates His people by promise.

Abraham could not manufacture Isaac. Sarah could not overcome her barrenness. Zion could not restore herself. Gentiles could not claim Abraham by ancestry. Humanity could not produce the new creation.

God acted. He kept His promise, sent His Son, and gave His Spirit. What human effort could never accomplish, God Himself brought to fulfillment through Christ.

And people who once appeared to stand outside Abraham’s family discovered that, in Christ, they had been welcomed into the inheritance promised long ago.

This is why Paul will not allow the Galatians to retreat into religious systems for securing what God has already freely given.

The church lives from promise before it lives from performance.

We obey not to manufacture our identity but because God has already given us one. We walk by the Spirit not to become God’s children but because, in Christ, we already are his children.

That is the startling message hidden inside Paul’s difficult comparison.

Sarah and Hagar are not an excuse for Christians to despise Israel.

They are Paul’s warning against turning God’s gift into human achievement.

And they are his announcement that the God who brought life from Sarah’s barren womb is still doing the impossible: creating one worldwide family, through the Messiah and by the Spirit, as children of the promise.

Bibliography

• Byrne, Brendan. “Jerusalems Above and Below: A Critique of J. L. Martyn’s Interpretation of the Hagar–Sarah Allegory in Gal 4.21–5.1.” New Testament Studies 60, no. 2 (2014): 215–231.
• de Boer, Martinus C. “Paul’s Quotation of Isaiah 54.1 in Galatians 4.27.” New Testament Studies 50, no. 3 (2004): 370–389.
• Di Mattei, Steven. “Paul’s Allegory of the Two Covenants (Gal 4.21–31) in Light of First-Century Hellenistic Rhetoric and Jewish Hermeneutics.” New Testament Studies 52, no. 1 (2006): 102–122.
• Dunn, James D. G. The Epistle to the Galatians. Black’s New Testament Commentary. Peabody, MA: Hendrickson, 1993.
• Ford, J. Jarrett. “The Meaning of ἀλληγορέω in Galatians 4.24 Revisited.” New Testament Studies 70 (2024).
• Hays, Richard B. Echoes of Scripture in the Letters of Paul. New Haven, CT: Yale University Press, 1989.
• Martyn, J. Louis. Galatians: A New Translation with Introduction and Commentary. Anchor Bible 33A. New York: Doubleday, 1997.
• Wright, N. T. “The Letter to the Galatians: Exegesis and Theology.”

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