What does the Bible say about the children of promise?

The concept of the children of promise, as articulated in Romans 9, underscores that not all who are physically descended from Abraham are children of God. Paul makes it clear that the distinction lies between those born of the flesh, like Ishmael, and those born of the promise, like Isaac. Isaac was chosen to fulfill God's covenant and purpose, illustrating that God's election is based on His will and promise rather than human effort or lineage (Romans 9:4-13). This emphasizes the sovereign grace of God in determining who are His true children, aligning with the theological stance that grace is not earned but freely given by God's choice and purpose.