In Genesis Chapter 21, we see the purpose, power, and faithfulness of God in His promise fulfilled. We also see how Sarah relied again on her own power and didn't rest in God's promise.
1. What are the three ways we can see in the first five verses that Isaac's birth is a result of divine intervention or the promise of God?
2. What are two ways we see Abraham obey God in the first five verses?
3. How does a review of the following passages of Scripture help us understand Sarah's views over time regarding her ability to have children?
4. According to the Guinness Book of World Records, at the time this Bible study's publication (February 2016), the oldest man to father a child did so at the age of 92 years and ten months; and the oldest woman to conceive naturally did so at the age of 59 years.
Because the Guinness rules require record verification, it seems unlikely the Guinness judges will consider the ages of Abraham (100) and Sarah (90) to be world records despite the authority of the Word of God.
And despite the authority of the Word of God and His demonstrated faithfulness, both Abraham and Sarah laughed when they were told by God that Sarah would give birth to a son for Abraham.
Of course, God knew their thoughts. He instructed Abraham to name the son Sarah would bear him Isaac (17:19), which in Hebrew means laughter. What was the effect of naming Abraham's son "laughter"?
5. Before Abraham had any children, he worried that he was childless and complained to God that a slave born in his house would be his heir. God responded that Abraham would have an heir and he would come from Abraham's own body (15:3-4).
Then Sarah gave Abraham her slave Hagar to be his wife so Sarah and Abraham could build a family by Hagar (16:1-3). After Hagar bore a son Ishmael to Abraham, God told Abraham that Sarah would have a son to which Abraham replies: "If only Ishmael were acceptable to you!" (17:18). Obviously Abraham loved his son Ishmael born of a slave in his house.
So Sarah has Isaac and then complains to Abraham about Ishmael. She asks that he and his mother be sent away so that the son of a slave will not be a co-heir with her son Isaac (21:10). She does this once Isaac is weaned and therefore beyond the feebleness of the first years of infancy (hence the feast). She also does this because she saw Ishmael mocking or laughing - presumably with Isaac as the target.
Verse 11 of Genesis chapter 21 tells us this was a very difficult thing for Abraham. In what two ways does God reassure Abraham about Sarah's request and convince him to send Hagar and Ishmael away?
6. Review Galatians 4:21-31. How does this New Testament passage help us understand how Christians today relate to this story of Isaac and Ishmael in Genesis chapter 21?
7. Sarah asked Abraham to banish Hagar and her son because she didn't want Ishmael to be a co-heir with her son Isaac (21:10). What was it that Isaac was to inherit as an heir to Abraham?
8. What was the advantage to Abimelech to enter into a treaty with Abraham; or, why might Abimelech have sought a treaty with Abraham?
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We pray this Bible Study on Genesis Chapter 21 has been a blessing to you.