Genesis

Genesis 21: God keeps His promised word

Begin in prayer

Before we read about Isaac's birth and God's care for Hagar's son, let us give thanks for His faithful word. Ask Him to show us the promised Savior and teach us to trust Him while we wait.

For Yahweh’s word is right. All his work is done in faithfulness.

Psalm 33:4

Everlasting God, please help us understand Your faithful word in this chapter. Show us Jesus, the promised Savior who brings believers into Your family. Make us more like Him, ready to obey You and hear people in need. Please bless our family with trust that rests on Your promise while we wait. In Jesus' name, Amen.

See where we're going

Sarah bears Isaac at the time God has promised, and Abraham names and circumcises him as commanded. Her laughter credits God for the child, whose weaning is marked by a feast. When Hagar's son mocks, Sarah demands that he leave, and God tells Abraham the promised line will continue through Isaac. Hagar and her son run out of water in the wilderness, where God hears the boy and shows her a well. God stays with him as he grows, while Abimelech recognises God's presence with Abraham and asks for an oath. The men settle a well dispute and make their agreement, and Abraham worships the everlasting God while living as a foreigner.

As you read Genesis 21, look for the answers:

Reflect together

Key truth

God faithfully keeps His word, giving the promised son and showing His care beyond Abraham's household.

God keeps His repeated promise about Sarah by giving Abraham a living son when the father is one hundred. Abraham names him Isaac and gives him the covenant sign on the eighth day, answering God's faithfulness with obedience. Isaac's name is tied to laughter, and Sarah credits God for the joy shared by those who hear. At the weaning feast a conflict over inheritance arises, and God directs Abraham to send Hagar and her son away. Isaac will carry the promised line, yet God also promises to make a nation from Abraham's other son. In the dry country around Beersheba, their water runs out, and God hears the boy where Hagar fears he will die. He opens her eyes to a well, keeping His word without making Ishmael the heir or telling us whether he believes. Abimelech recognises God's presence with Abraham, and their agreement settles a well dispute while the patriarch remains a foreigner who worships. The everlasting God's faithfulness reaches its saving fulfillment in Christ, through whom believers become heirs by promise (Galatians 4 verses 4 to 7).

How does Genesis 21 show us that God faithfully keeps His word, giving the promised son and showing His care beyond Abraham's household?

God gives the promised son at the time He has named.

The LORD does for Sarah what He has said, and she gives Him the credit for her laughter. Abraham obeys the commands to name Isaac and circumcise him on the eighth day. The covenant sign follows God's gift, and it cannot produce the faith that only God gives. Isaac belongs to the family line leading to Jesus, the Savior through whom God's promise of salvation is fulfilled.

God names the heir and hears the boy in the wilderness.

God tells Abraham to follow Sarah's demand in this matter, since the promised line will continue through Isaac. He also promises a nation for Hagar's son, and His hearing in the wilderness keeps that word. Ishmael is a youth, and the text gives no words for his cry or assurance of his salvation. Paul uses the two households to teach that believers inherit through God's promise, free from earning their place by law.

God sustains Abraham as a stranger who calls on His name.

Abimelech asks for honest dealing because he recognises that God is with Abraham. A seized well threatens the water needed for life, and Abraham raises the wrong directly with the king. Seven lambs become a witness that he dug the well, and the men swear an agreement. Abraham plants a tamarisk and worships the everlasting God, remaining a foreigner even after the dispute is settled. Human agreements last only as long as those who keep them, while God's saving promise stands secure in the risen Christ.

Memorise

Yahweh visited Sarah as he had said, and Yahweh did to Sarah as he had spoken.

Genesis 21:1

Looking to Jesus in my life

Ask yourself in your heart, where am I trying to earn what God gives through faith in Jesus?

Sarah says, “God has made me laugh.” Her son is born “at the set time of which God had spoken to him”. God has kept His promise through years of waiting, and His mercy also hears a boy outside the chosen line.

That faithful God sent His Son at the appointed time to redeem sinners and bring them into His family. Jesus came through Isaac's family line, yet the salvation He gives reaches people of every nation. At the cross He bore the punishment of His people and paid their debt in full. He rose from death, and His finished sacrifice is enough to bring every believer into peace with God.

Please turn from trying to earn a place with God, and trust the Son He has given. Everyone who repents and believes in Jesus receives forgiveness and belongs to God's family by grace. If you trust Him, you can praise the everlasting God while you wait, and care for people beyond your own household. His word has not failed, and His Son will keep all who come to Him.

Parent's note

Tell your children how God keeps His word and gives salvation through His promised Son. Jesus bore His people's penalty and rose, so call each child to turn from sin and trust Him for forgiveness. Please do not tell them they are saved just because they grew up in a Christian home. Pray that God would give each child a new heart, without resting hope on a family connection or outward sign.

Pray together

Please thank God for His faithful word and bring Him the effort to earn His favor that the heart question has exposed. Ask Him for faith in Jesus. Invite each child to thank Him for a promise or ask for help if they want to.

But when the fullness of the time came, God sent out his Son, born to a woman, born under the law, that he might redeem those who were under the law, that we might receive the adoption of children.

Galatians 4:4-5

Father, thank You for keeping Your word and sending Your Son to redeem sinners. Please forgive our attempts to earn what You give by grace, and lead us to trust Jesus. Help us obey You with thankful hearts, hear people in need, and speak truth as we seek peace with others. Amen.