Why is understanding the children of the promise important for Christians?

Understanding who the children of the promise are is vital for Christians as it underscores the principle that salvation and acceptance by God are based on faith rather than ethnic lineage or personal merit. Paul makes this distinction clear in Romans 9:7-8, asserting that being a descendant of Abraham physically does not guarantee being a child of God. Instead, those who trust in Christ—'the children of promise'—are considered true heirs. This truth encourages believers that their identity and relationship with God are secure, rooted in faith, rather than in the flesh or human efforts.