Paul has taught the Galatian Christians that they were fully children of Abraham the moment they believed in Christ (3 v 7). Now he uses the illustration of Abraham's two sons, Ishmael and Isaac, to make his point in a final, dramatic way.
Two sons: the difference
Read Galatians 4:21
• What does it mean to be “under the law” (v 21)?
Paul’s point isn’t about what we are obeying: it’s about what we’re relying on.
Read Genesis 16:1, Genesis 18:10, Genesis 21:1
• What are the differences in the births of these two sons (Galatians 4 v 23)?
• What does Paul say each birth mother represents (v 24-26)?
• What is the difference between the “children” of the two women?
This would have been shocking to Jewish ears. The residents of Jerusalem would have regarded Sarah as their mother, and Hagar as the mother of the Gentiles. Paul has in effect reversed things.
That’s because trusting in God's law, as Jerusalem is doing, enslaves. It's Paul's Christian brothers who are “children of the promise” (v 28), because they are trusting in Christ and so are members of the true “Jerusalem” (v 26)—heaven.
The basic teaching is that the gospel not only makes absolutely anyone a child of God, but that the most proud and moral and religiously “able” are often the ones left out of God's family.
The gospel reverses the world's values.
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APPLY
• How will this change the way you look at the members of your church?
• What is the difference between a “religious” approach to God, and a Christian one?
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Two sons: the relationship
Read Galatians 4:29
• In verse 29 Paul draws another parallel between the two brothers. What is he saying about the relationship between Ishmael and Isaac then?
• What point is he making about those who trust in works-righteousness and those who trust in Christ now (end of v 29)?
• Why is this the case, do you think?
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APPLY
• Why do religious people need the gospel?
• How should you expect religious people to react to the gospel?
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This devotional is taken from Explore—a daily Bible-reading devotional from the good book company which enables you to engage with Scripture and which will encourage, equip and inspire you to live for Christ. Explore features contributions from pastors such as Dr Timothy Keller, Mike McKinley and Tim Chester.
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