At a glance
Ishmael and Isaac grew up under the same roof, and separating what looks alike from the outside always feels severe.
Only one of the two could inherit, and grace and self-effort, like fire and water, were never meant to be mixed.
Relevant Scripture
“Nevertheless what saith the scripture? Cast out the bondwoman and her son: for the son of the bondwoman shall not be heir with the son of the freewoman.”
Galatians 4:30 KJV
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Chapter 6 of the LibriVox recording of According to Promise, streamed directly from the Internet Archive (public domain, CC0).
UECF.NET summary
Sarah's demand that Hagar and Ishmael be sent away is one of the harder scenes in Genesis, and Spurgeon does not soften it. He reads it instead as Scripture's own verdict that the household of promise cannot indefinitely contain, on equal footing, a principle that ultimately opposes it. Paul confirms the reading in Galatians, applying it directly to law and grace: the two cannot jointly inherit, however comfortably they may have coexisted for a season.
For Spurgeon's readers, the chapter presses toward a serious, sometimes painful, form of self-honesty about what a person is actually resting on for salvation. Someone may sincerely mix a little trust in Christ with a good deal of quiet confidence in their own effort, respectability, or church standing. The chapter insists that this mixture cannot ultimately stand; either grace alone bears the whole weight, or self-effort will, in the end, be shown for what it is — unable to inherit.
Spurgeon is careful to note that the parting was for Ishmael's ultimate good as much as Isaac's, since Genesis records that God cared for Ishmael afterward and made of him, too, a great nation, even though not the nation of promise. The chapter's aim is not harsh exclusion but clear sight: what cannot inherit together must, at some point, be honestly told apart, so that a soul may rest wholly on grace rather than on a mixture that cannot ultimately hold weight.
Main theological themes
- Grace and self-effort cannot jointly inherit; one principle or the other must finally govern a person's confidence before God
- The pain of separating things that have long coexisted, even within one household or one heart
- God's continuing care for Ishmael even after the parting, showing the decision was not cruelty but clarity
Key ideas
- A mixed confidence — partly Christ, partly self — feels stable for a season but cannot ultimately inherit.
- Paul applies the Genesis story directly to law and grace, not merely to an ancient family dispute.
- Clarity about what a person is resting on is kinder, in the end, than a comfortable but false mixture.
- God's care for Ishmael afterward shows that this parting was about inheritance, not about God's compassion.
Important concepts
- Casting out the bondwoman — Paul's picture, from Genesis 21, for decisively setting aside any confidence in self-effort as the ground of a right standing before God.
- Joint heirs impossible — The principle that grace and law-keeping cannot together support a person's confidence before God; one must finally give way to the other.
Related Bible references
Practical Christian application
- Take an honest inventory this week of what you are really resting on for your standing before God.
- Where you find a mixture of grace and self-confidence, ask God to make grace alone your ground.
- Extend the same clarity kindly to a conversation with someone still mixing faith and self-effort.
Questions for study
Reflection questions
- Where might you still be quietly mixing confidence in yourself with your trust in Christ?
- Why do you think this kind of parting can feel harsh even when it is ultimately kind?
- How did God's continued care for Ishmael shape the way you read this difficult story?
Small-group discussion
- Why can grace and self-effort not simply coexist as equal partners in a person's confidence before God?
- How should a church handle members who seem to mix grace and self-reliant religion, without being unkind?
- What does Ishmael's later blessing (Genesis 21:20) teach about God's character even in a hard providence?
These notes are an original UECF.NET study companion and are not a reproduction of Spurgeon's text. According to Promise (1900) is in the public domain — read the complete free text at the Internet Archive, or listen to the full LibriVox recording above and at archive.org. Scripture quotations above are the King James Version.