Galatians 4:21-4:31 is the last of Paul’s arguments for the justification by faith alone. This passage closes the doctrinal section of the letter
- Chapters 1 and 2 are biographical where Paul defends his authority to teach the gospel and minister as an apostle.
- Chapters 3 and 4 are doctrinal where Paul defends the doctrine of justification by faith.
- Chapters 5 and 6 are practical where Paul applies the doctrine he has just taught.
This section is not so much an argument as it is an illustration of the argument that he’s already made. To contrast the bondage of the law with freedom in Christ, Paul makes a comparison with Ishmael and Isaac. Both sons had the same father but only one inherited the promise, the one who had faith.
Paul illustrates that it is not enough to claim that Abraham is your father. The real question is who is your mother.