Take some time to read Genesis 21:1–21 and Psalm 113. Here’s an excerpt:
Now the Lord was gracious to Sarah as he had said, and the Lord did for Sarah what he had promised. Sarah became pregnant and bore a son to Abraham in his old age, at the very time God had promised him. Abraham gave the name Isaac to the son Sarah bore him. When his son Isaac was eight days old, Abraham circumcised him, as God commanded him. Abraham was a hundred years old when his son Isaac was born to him. Sarah said, “God has brought me laughter, and everyone who hears about this will laugh with me.” And she added, “Who would have said to Abraham that Sarah would nurse children? Yet I have borne him a son in his old age.”—Genesis 21:1–7
Core Truth: The advance of God’s mission does not depend on traditional human power structures or practices.
God consistently, relentlessly, and faithfully keeps his promises to his people in Genesis 12–50. These chapters use the themes of childlessness and the reversal of the firstborn’s privilege to teach us key truths about God and God’s mission.
Blessing the Childless
Childlessness recurs throughout Genesis 12–50. It affects Abraham/Sarah and Isaac/Rebekah. Childlessness functions to mark God’s people as the product of his grace and not human power. God calls Abraham and Sarah to be the wellspring for a new humanity that exists for the sake of the nations. Abraham obeys and trusts God, but he has no son. God renews his promises to Abraham in 15:1–6. His trust in God is reckoned as righteousness (15:6), but there is still no son. In chapter 16, Abraham and Sarah take matters into their own hands by conceiving a child through Sarah’s slave, Hagar. This was an acceptable practice, but God planned a miraculous birth. Childlessness is no obstacle for God. Thus, late in life and according to God’s promise (18:10), Sarah bears a son named Isaac. Isaac and Rebekah face the same challenge. God opens Rebekah’s womb in response to Isaac’s petition, and she gives birth to twins: Esau and Jacob.
God’s ability to bless the childless recurs throughout the Old Testament. In Psalm 113, the psalmist declares God’s care and compassion for the marginalized. Verse 9 announces, “[the Lord] settles the childless woman in her home as a happy mother of children. Praise the Lord.”
Likewise, Isaiah (54:1) proclaims, “ ‘Sing, barren woman, you who never bore a child; burst into song, shout for joy, you who were never in labor; because more are the children of the desolate woman than of her who has a husband,’ says the Lord.” Isaiah speaks these words as a means of encouraging those waiting for God’s salvation.
What is the point of this theme? God’s salvation is not dependent on human power or ability. God’s mission depends on God’s strength and power. God demonstrates this by multiplying descendants for Abraham through couples unable to bear children. It also reminds us that God works through people whom many communities marginalize.
Reversal of the Privilege of the Firstborn
In Genesis 12–50, Isaac supplants Ishmael, Jacob gains the elder Esau’s birthright, and Joseph rules over his family. The firstborn son carried a position of power in the ancient world. This was a means of insuring the success and prestige of the family by investing the family’s resources in the firstborn. God does not need the status quo power structures of humanity to advance his mission. God works through the powerless, the humble, and the overlooked. This means that God often bypassed the firstborn in favor of a younger son. We saw this first in the Cain and Abel story.
In Abraham’s narrative, Ishmael is his firstborn. Abraham beget Ishmael with his own strength, but God intended something greater. In Genesis 18, God renews his promise that Sarah will bear a child (18:10). Abraham and Sarah were well beyond the normal child-bearing years. God keeps his word and Genesis 21:1–7 records the birth of Isaac. Abraham is one hundred years old at Isaac’s birth. Ishmael was approximately fourteen years old. There is instant tension between Sarah/Isaac and Hagar/Ishmael. Sarah demands that Abraham expel Hagar whom she refers to as “that slave woman” and Ishmael whom Sarah calls “[Hagar’s] son” (21:10). The expulsion of Hagar and Ishmael is tragic from a relational perspective, but God steps in to redeem it. Ishmael is a son of Abraham after all. God’s blessing extends to those in proximity to Abraham as well, so in 21:13 God affirms that Ishmael will indeed become a “great nation” too. Genesis 25:12–18 records the fulfillment of this promise. Ishmael becomes the father of twelve sons who become princes of a twelve-tribe confederation analogous to the line of Abraham, Isaac, and Jacob.
The rivalry between Esau and Jacob begins at conception (25:33). At birth, Esau arrives first with Jacob hanging onto his heel. But Rebekah already knows that God has ordained the elder to serve the younger. In God’s plan, it will be Jacob and not Esau through whom the lineage of God’s people will continue. This choice does not depend on Jacob’s character in any way. Jacob is deceitful and a rogue. God’s choice of Jacob does not render Esau’s life meaningless or a failure. Esau remains linked to the family of blessing and thus is blessed. He accumulates wealth for himself (33:9) and becomes the father of the Edomites (36:40).
Lastly, the rivalry between Joseph and his brothers dominates Genesis 37–50. Joseph is the eleventh of twelve sons. Yet Jacob favors him because he was the firstborn son of his beloved wife, Rachel. This causes tension and jealousy within the family and his brothers sell him into slavery. Joseph ends up in Egypt where God prospers him. After Joseph interprets the dream of Pharaoh, he elevates Joseph from imprisoned slave to a leadership role second only to himself. God’s providential care for his people is evident in Joseph’s extraordinary story. Joseph rises to power precisely in time to create a safe haven in Egypt so that God’s people can persevere and grow during a period of severe famine.
In all of these stories, God demonstrates his power to save by working through a younger son rather than the firstborn. This subverts a claim to human power in the advance of the gospel.
God’s mission moves forward by his grace. God makes and keeps promises. God overcomes broken family relationships, ill intentions, and even human infertility to advance the family through whom the nations will be blessed (Gen. 12:3b). God’s people grow from a childless couple to a substantial presence in Egypt. God reverses cultural bias toward the firstborn to advance his kingdom. Genesis 3–11 demonstrates humanity’s inability to find its own way and its penchant for spectacular failure. The stories of Abraham, Isaac, and Jacob point to a new hope. This hope finds its roots in God’s faithfulness and commitment to his people. The themes of childlessness and the flipping of the privileged role of firstborn serve to proclaim this.