Sarah vs Hagar: Part 1: The Choice We All Make: Gal 4:21-31

In Galatians 4:21–31, Paul uses the story of Abraham’s two sons—Ishmael and Isaac—to make a bold, powerful point about faith vs legalism.

Ishmael vs Isaac

Ishmael was born through Hagar, the slave woman. His birth came about because Abraham and Sarah tried to force God’s promise through human effort. It was natural, logical, and based on pressure—not on faith. That’s why Paul says Ishmael was born “according to the flesh.” No miracle. No supernatural move. Just effort, striving, and stress.

Isaac, on the other hand, was born to Sarah, the free woman. His birth was impossible without God. It required faith. It was a promise fulfilled by grace—not by works. It required trusting God in all levels.

Our Produce

Sometimes when we slide into performance mindset, and legalism, it is always for the good-reasons. We may think it helps in our spiritual life, but the fruit of all that is Ishmael.

However, when we live according to the spirit, it requires faith, trust in God who promised and just living it out. When you do so, because you are of faith, you are an heir to the promise.

Paul tells us this story isn’t just ancient history—it’s an allegory. Hagar and Sarah represent two covenants: Law vs. Grace. Effort vs. Promise. Slavery vs. Freedom.

Here are Paul’s three key takeaways:

1. You, Christian, are like Isaac—born of the Spirit, supernaturally (John 3:3,5) not the flesh. You’re a child of promise, not performance(Gal 3:9,22,29). So don’t live like you’re still trying to earn God’s approval. (Gal. 4:28)
2. Expect resistance. Just as Ishmael mocked Isaac, legalistic religion will always oppose grace. Paul likens this to the persecution he and other believers faced from those still clinging to the law. (Gal. 4:29). It happened in Paul’s day, and it happens even now.
3. Cast out the old. Just as Abraham sent Hagar and Ishmael away, we must reject any teaching that tries to mix law with grace. They can’t coexist. Law brings bondage—grace brings inheritance. (Gal. 4:30)

Paul wraps it up clearly in verse 31:

We are not children of the slave woman, but of the free. (Gal 4:31)

So let’s live like it—free, full of promise, and resting in what Jesus has already done.