Genesis 21:1-7 – Promise fulfilled (sermon notes)
[Notes of a sermon preached at St Andrew’s Eaton (Norwich) on 6th September 2026]
“It shall greatly help ye to understand the Scriptures if thou mark not only what is spoken or written, but of whom and to whom, with what words, at what time, where, to what intent, with what circumstances, considering what goeth before and what followeth after.” (Coverdale, prologue to his 1535 Bible translation)
1. What goeth before?
The birth of Isaac ends the suspense that began in Gen 11:30 — ‘Now Sarai was barren; she had no child.’
Yet the Lord had been saying to Abraham: “I will make of you a great nation…In you all the families of the earth shall be blessed” (Gen 12:1-3)…”To your offspring I will give this land” (Gen 12:7)…“Your descendants will be as numerous as the stars of the sky” (Gen 15:5)
How could a childless couple become a great nation? How could their descendants be as numerous as the stars? How could they inherit the land? How could they bring blessing to all the families of the earth?
Unsurprisingly, the faith of Abraham and Sarah had experienced many twists and turns. They had scoffed at God’s promises. They had tried to do things their own way (Hagar/Ishmael). And all the while they had been growing older, and the fulfilment of God’s promises must have seemed more and more unlikely.
Yet Abraham’s faith triumphed in the end. And at last the longed-for son arrives, the climax of 25 years of waiting. Sarah’s laughter of disbelief is transformed into the laughter of relief and of joy: v6f – “God has brought laughter for me; everyone who hears will laugh with me.” And she said, “Who would ever have said to Abraham that Sarah would nurse children? Yet I have borne him a son in his old age.”
And they all lived happily ever after(?)
2. What followeth after?
The story of marriage does not end with the engagement or with the wedding. The story of employment does not end with the interview or being offered the job. The story of God’s promises to Abraham does not end with Sarah’s pregnancy or with the birth of her son.
The birth of Isaac was not the end; it was not the beginning of the end. It was, perhaps, the end of the beginning.
The fulfilment of God’s promises to Abraham was still very incomplete. According to Heb 11:13, Abraham ‘died in faith without having received the promises’. By the end of his life, all he had was one plot of land and one son.
What, then, of those promises of a multitude of descendants? What about the prospect of a land of their own? What about the prediction that through Abraham’s descendants all the families of the earth would be blessed?
And so the story continues to unfold: Abraham – Isaac – Jacob – twelve tribes – Egypt – exodus – wanderings – promised land – judges – monarchy – divided kingdom – exile – partial return – 400 years further waiting.
When we enter the world of the New Testament, God’s ancient people have not been forgotten.
Mt 1:1 – ‘Jesus the Messiah, the son of David, the son of Abraham.’’
Lk 1:54f – “He has helped his servant Israel, in remembrance of his mercy, according to the promise he made to our ancestors, to Abraham and to his descendants forever.”
Jesus himself declared that his mission was, in the first place, “…to the lost sheep of the house of Israel” (Mt 10:6; 15:24).
But, you remember, the promise to Abraham was that through him all the families of the earth would be blessed.
And the OT itself anticipates the time when God’s salvation would embrace all nations: Melchizedek (king of Salem), Rahab (Canaanite), Ruth (Moabite), Naaman (Syrian).
Psa 2:7 – “Ask of me, and I will make the nations your inheritance.”
Isa 49:6 – “I will give you as a light to the Gentiles, that my salvation may reach to the end of the earth.”
And so, moving forward again to the New Testament:
Mt 28:18 – “Go and make disciples of all nations,”
Acts 1:8 – “But you will receive power when the Holy Spirit has come upon you; and you will be my witnesses in Jerusalem, in all Judea and Samaria, and to the ends of the earth.”
Romans 1:16 – ‘For I am not ashamed of the gospel; it is the power of God for salvation to everyone who has faith, to the Jew first and also to the Gentile.’
Gal 3:29 – ‘There is neither Jew nor Gentile…If you belong to Christ, then you are Abraham’s seed, and heirs according to the promise.’
Faith, hope, love
Love: Lk 13:34 – “Jerusalem, Jerusalem, the city that kills the prophets and stones those who are sent to it! How often have I desired to gather your children together as a hen gathers her brood under her wings, and you were not willing!”
Rom 10:1 – ‘Brothers and sisters, my heart’s desire and prayer to God for [Israel] is that they may be saved.’
Charles Simeon: ‘‘The conversion of the Jews was perhaps the warmest interest of his life. He actively promoted the work of the Society for Promoting Christianity among the Jews [CMJ]. On hearing of a Jew who had recently embraced the Christian faith, he wrote, “O that the whole nation might remember themselves, and turn to the Lord!”’
Faith: For this, I refer you to our second reading [Romas 4]. Abraham’s heirs are not those who are his physical descendants, but those who share his faith.
Now faith is a slippery word. Biblical faith is not superstition. It is not wishful thinking. It is not credulity. Christian faith is, rather, knowing and believing the truth about Jesus Christ and committing oneself to him.
Faith is the eye that looks to Christ. It is the foot that runs to him. It is the hand that receives him.
Hope – Rev 7:4 – ‘And I heard the number of those who were sealed, one hundred forty-four thousand, sealed out of every tribe of the people of Israel.’
Rev 7:9 – ‘After this I looked, and there was a great multitude that no one could count, from every nation, from all tribes and peoples and languages, standing before the throne and before the Lamb.’
This gives us hope for renewal in our day.
Whitefield: ‘The Scriptures are so far from encouraging us to plead for a diminution of divine influence in these last days of the gospel that on the contrary, we are encouraged to expect, hope, long, and pray for larger and more extensive showers of divine influence than any former age hath ever yet experienced.’