Verses 28-30 of Paul’s allegory is based on Genesis 21:9-10. Isaac was continually persecuted by his older half brother Ishmael. Eventually, Ishmael and his mother Hagar were expelled because Ishmael had no standing in God’s eyes as heir of Abraham. Just like Isaac, the New Testament saints were children of promise. Just as Isaac was subject to Ishmael’s persecution (see Gen. 21:9), so the early Christians were subject to persecution from the legalists. By applying this quote from Genesis 21:10, Paul commands the Galatians to get rid of the legalizers. Their work does not have the authority or blessing of God. It must come to an end. The Galatians must choose to be free and act on that choice by expelling the Judaizers.
In creating a parallel between the story from Genesis and the Galatians’ situation, Paul points out that (1) the persecution by the Jewish legalists of his day was not unexpected, and (2) it would not go on indefinitely because the legalists would soon be cast out.
In applying the truth from the biblical illustration, Paul made three comparisons, as we will see shortly.
28 And you brethren, like Isaac, are children of promise. 29 But as at that time he who was born according to the flesh persecuted him who was born according to the Spirit, so it is now also. 30 But what does the Scripture say? “Cast out the bondwoman and her son, For the son of the bondwoman shall not be an heir with the son of the free woman.” 31 So then, brethren, we are not children of a bondwoman, but of the free woman. (NASB)
Key Takeaways:
- We, as Christians, are children of promise. Let us live in that promise and freedom with thanksgiving, and not in bondage to legalism and works.
- Justification is by grace through faith and not by observing rules or performing rituals and works.
- Striving to a legalistic, works based religion brings no inheritance. But our salvation by grace through faith bring an inheritance full of incomprehensible riches
Closer Look:
Verse 28: Comparison one, Paul compared the birth of Isaac to that of Christians. As “Isaac” experienced a supernatural birth and was a child by means of a promise, so each believer experiences a supernatural birth (John 3:3, 5) and is a recipient of the promise of salvation (Gal. 3:9, 22, 29). As “children of promise,” Christians are in a distinct category and should not live as children of bondage.
Verse 29: Comparison two, the apostle compared Ishmael’s persecution of Isaac to the false teachers’ opposition to believers. Abraham celebrated the weaning of Isaac with a banquet. On that occasion Ishmael mocked Isaac, laughing derisively at the younger boy, since Ishmael was the elder son and assumed he would be heir to his father’s estate (cf. Gen. 21:8–9). That early animosity has been perpetuated in the two peoples which descended from the two sons of Abraham and is seen in the current Arab-Israel tensions. Paul likened the Judaizers to Ishmael as those who were born out of legalistic self-effort; he charged that they continued to persecute the true believers who were “born according to the Spirit.” With few exceptions Paul’s persecution came from the Jews, the people in bondage to the Law.
Verse 30: Comparison three, Paul compared the action of Abraham to the obligation of the Galatians. When Sarah observed Ishmael mocking Isaac, she asked Abraham to cast out or expel the slave woman (“bondwoman”) and her son lest Ishmael become a joint heir with Isaac. And God granted Sarah’s request (cf. Gen. 21:10, 12). This reminded the readers that Law observance brought no inheritance in the family of God, and it also charged them to excommunicate the Judaizers and those who accepted their false doctrines. A fundamental incompatibility remains between Law and grace, between a religion based on works and a religion based on faith.
Verse 31: In conclusion, Paul affirmed that he and the Galatian believers were “not children of the bondwoman” who was driven away and was denied a share in the inheritance. Rather all believers are children “of the free woman,” “heirs of God and fellow heirs with Christ” (Rom. 8:17, NASB). The phrase “so then” represents the conclusion of the previous section, while the “therefore” in 5:1 signals that Paul is going to apply this spiritual truth to the lives of the Galatian believers. To be “children of a bondwoman” is to be enslaved to the covenant from Mount Sinai (4:24, 25), the Law of Moses. To be “of the free woman” is to follow Abraham’s example of faith (3:6-9), to be “born according to the Spirit” (3:2; 4:29), and to be destined for the “Jerusalem above” (4:26).
Chapter 4 concluding thoughts and summary:
Erroneously, the Judaizers believed that faith alone in Jesus Christ was not enough for salvation and Christian maturity. Unfortunately, the Judaizers were getting the Galatians to follow their line of thinking, and consequently, the Galatians were no longer on the same page with God and His grace.
The result of the Judaizers’ error was of great significance. The eternal destinies of people are jeopardized when grace is clouded over by legalism. In addition, Christianity is extremely unattractive when presented with a legalistic flavor. Legalism repels, while grace attracts. Fortunately, for the Galatians and for modern readers, Paul tackled this legalistic distortion head on.
Thank God, the Christian is set free from the curse of the Law and the control of the Law. We must cast off the yoke of legalism and works based theology (““Cast out the bondwoman and her son”). It may pain us deeply, as it did Abraham; but it must be done. To attempt to mix Law and grace is to attempt the impossible. It makes for a frustrated, barren Christian life. But to live by grace, through faith, gives one a free and fulfilling Christian life.
So what, then, is the secret? The Holy Spirit. And it is this secret that Paul will share in the closing “practical” chapters of the letter. Meanwhile, you and I need to beware to not let legalism and works creep back into our lives. If they have—let us cast them out.
Chapter 4 Principles:
- External rules and restrictions are an indication of childish immaturity.
- Reverting to the law is regressing to spiritual childhood.
- Grace gives you a deeply personal relationship with God. By grace, we are brought into God’s family and made heirs.
- Grace brings believers together, while law separates God’s family. Legalism brings bondage, grace brings freedom.
Chapter 4 Applications:
- Christians can rest in the security that we are the recipients of an unchangeable covenant with God.
- You can praise God that He is continuously maturing you toward spiritual adulthood. He wants you to know Him better and more intimately
- Decide what you think is the primary privilege and responsibility of being a spiritual adult. Think about what it means to grow in spiritual adulthood. What does that look like for you? Think also of the privileges and responsibilities that you have as you grow. Think of ways to help younger believers grow as you reflect on things that may have caused you to stumble.
- Remember, you can enjoy the fact that God is your Father who loves you deeply. He loves you so much that He sent His only Son to die for you. You are deeply loved. I know not all of us may have had good experiences with our earthly fathers, but the Almighty Father loves you deeply and will never forsake you.