Shared ground
Paul begins by rejecting the idea that God’s word has collapsed because many ethnic Israelites are not responding as he hopes (v.6). His first move is definitional: “Israel” can mean the larger family line, but it can also mean a narrower “Israel” within Israel (v.6). So the problem is not that God promised one thing and then failed; it is that people have assumed the promise applied in a way Scripture itself does not support.
Paul backs this with Abraham’s family story. Being Abraham’s “offspring” (seed) does not automatically make someone a “child” in the sense that matters for the promise (v.7). Scripture itself singled out Isaac as the line through whom the promise would be carried forward (v.7, v.9). Paul summarizes: not “children of the flesh” (mere biological descent) but “children of the promise” are counted as the offspring that continues the promise-line (v.8).
He then adds a second example to sharpen the point: Jacob and Esau share the same mother and father, and God’s statement about them was given before birth and before either had done good or bad (vv.10–12). This shows, at minimum, that the continuation of the promise-line is not simply a result of birth order or later achievements. Paul ends the set of proofs with a later Scripture line contrasting Jacob and Esau (v.13).
Where interpretation differs
1) Is Paul mainly talking about individuals or about family lines / peoples?
Some readers think Paul’s point is primarily about God choosing certain individuals for a saving relationship, using Jacob and Esau as examples. Others think Paul is mainly tracking which family line carries forward the covenant story (Isaac not Ishmael; Jacob not Esau), and that the later “Jacob/Esau” language can also refer to the peoples who come from them.
2) What does “not of works” mean here (v.11)?
Some take it broadly: God’s choice is never grounded in any human action, whether good or bad, and this illustrates how God chooses. Others take it more narrowly: in this argument, “not of works” means the promise-line was not determined by the twins’ later behavior or merit; it was determined by God’s prior call.
3) What does “loved” / “hated” mean in v.13?
Some read the words as strong personal affection versus personal rejection. Others read them as relational priorities in the covenant story: one is chosen for the promise-line and the other is not, without claiming God had the same kind of attitude toward each individual’s eternal fate.
Why the disagreement exists
The text does two things at once: it talks about concrete ancestors (Isaac, Jacob, Esau) and it uses them to explain the present puzzle about “Israel” (v.6). That creates real questions of scope. Also, Paul emphasizes timing (“before they were born,” v.11) and contrasts “works” with God’s “call” (v.11), which can sound like a general principle. Finally, the last quotation (v.13) comes from a later biblical context that many readers think speaks about peoples as well as persons, so interpreters differ on how directly Paul applies it here.
What this passage clearly contributes
Explicitly, Paul argues that God’s word has not failed (v.6) because Scripture itself shows that belonging to the promise-line has never been identical with physical descent (vv.7–9). “Israel” and “Abraham’s children” are not purely biological categories in Paul’s argument (vv.6–8). He also explicitly stresses that God’s statement regarding Jacob and Esau came prior to their actions, and he links this to God’s purpose in choosing and to God’s calling rather than to “works” (v.11). The passage therefore contributes a scriptural rationale for why many ethnic Israelites can be outside the group Paul is discussing as “Israel,” without implying that God’s promise has failed.