God Keeps His Promises – Genesis 21:1-7

This chapter records several key events that take place in Abraham’s journey of faith as he reaches the milestone of 100 years of age. There is:

• The fulfillment of God’s promise with the birth of Isaac (Vs. 1-7).
• The separation of Hagar and Ishmael from Abraham’s camp (Vs. 8-21).
• The covenant between Abimelech and Abraham (Vs. 22-34).

In this sermon we focus on the fulfilment of God’s promise to Abraham and Sarah. We can be encouraged in the faithfulness and reliability of God’s Word.

The Miracle of Isaac’s Birth (Vs. 1-2)

Concerning the birth of Isaac, Robert Candlish, a famed Scottish pastor of the 1800s, said, “If there be an occasion on earth fitted to call forth the songs of heaven, next to the birth of Jesus, and not second to the birth of his forerunner John, it is the birth of Isaac. Upon no event, between the fall and the incarnation, did the salvation of men more conspicuously depend.”

The Performance of this Miracle (Vs. 1-2)

In the miracle birth of Isaac we are reminded of several truths about the Person and Character of the God we serve.

1. The Faithfulness of God’s Word (Vs. 1, 2b)
   1. Isaac’s birth represented the fulfillment of God’s promises. God had promised to make of Abraham a great nation that would bless the whole world (12:1-3). Then He repeatedly promised to give the land of Canaan to Abraham’s descendants (17:7) and to multiply them greatly (13:15-17). Abraham would be the father of the promises seed (15:4), and Sarah (not Hagar) would be the mother (17:19; 18:9-15).
   2. God’s faithful fulfilment of His Word is emphasised three times in these two verses.
      1. “And the LORD visited Sarah as he had said” (Vs. 1a)
      2. “the LORD did unto Sarah as he had spoken” (Vs. 1b)
      3. “at the set time of which God had spoken to him” (Vs. 2b)
   3. We are reminded of the absolute and total reliability of God’s Word.
      1. Psalm 33:11 “The counsel of the LORD standeth for ever, the thoughts of his heart to all generations.”
      2. Psalm 100:5 “For the LORD is good; his mercy is everlasting; and his truth endureth to all generations.”
      3. John 17:17 “Sanctify them through thy truth: thy word is truth.”
      4. Proverbs 30:5 “Every word of God is pure: he is a shield unto them that put their trust in him.”
   4. Joshua’s testimony to the promises of God. “And, behold, this day I am going the way of all the earth: and ye know in all your hearts and in all your souls, that not one thing hath failed of all the good things which the LORD your God spake concerning you; all are come to pass unto you, and not one thing hath failed thereof.” (Josh. 23:14)
   5. Solomon’s testimony to the promises of God. “Blessed be the LORD, that hath given rest unto his people Israel, according to all that he promised: there hath not failed one word of all his good promise, which he promised by the hand of Moses his servant.” (1 Kings 8:56)
   6. 2 Cor. 1:20 “For all the promises of God in him are yea, and in him Amen, unto the glory of God by us.”
   7. 2 Peter 1:4 “Whereby are given unto us exceeding great and precious promises: that by these ye might be partakers of the divine nature, having escaped the corruption that is in the world through lust.”
2. The Perfectness of God’s Ways (timing) (Vs. 2b)
   1. Notice that Isaac’s birth occurred “at the set time of which God had spoken” (Vs. 2) That means it happened according to God’s perfect timing. Remember, God fulfills His promises in His time and in His way.
   2. This is often where we struggle. As believers, we believe God keeps His Promises but our faith then gets tested when it comes to:
      1. The waiting for God to accomplish His will.
      2. The way God accomplishes His will.
   3. Hebrews 6:12 reminds us that it is “through faith and patience inherit the promises.”
   4. John Butler writes, “God is always on time, in time, at the right time, at the best time, and at the promised time…. If we want to keep our lives from many troubles, we must submit to God’s set times and adjust our walk to God’s cadence.”
3. The Powerfulness of God’s Working (Vs. 2a)
   1. This truth is also emphasized three times.
      1. “For Sarah conceived, and bare Abraham a son in his old age” (Vs. 2a)
      2. “And Abraham was an hundred years old, when his son Isaac was born unto him.” (Vs. 5)
      3. “for I have born him a son in his old age” (Vs. 7)
   2. God demonstrates His power through the fulfillment of His promises. The birth of Isaac is a reminder that God’s power is unlimited and that He can do anything. God often sets the stage for the fulfillment of His promises with multiple impossibilities in order to magnify Himself. No doubt God also does it this way so that we won’t try and take the credit for what God has done.

The Picture of this Miracle

1. How it pictures the Saviour. In the birth of the promised seed to Abraham and Sarah, we can’t but see a foreshadowing of the birth of the Messianic Seed, the Lord Jesus Christ.
   1. Both births were foretold. They were both promised sons.
   2. Both had their names revealed before birth. Isaac meaning “laughter” and Jesus meaning “Saviour”.
   3. Both involved the miracle working power of God for the conception to take place. In the case of Abraham and Sarah, God did a miracle in both their bodies so that Isaac could be conceived. In the case of Christ, His conception was an even greater in that He was conceived by a direct act of the Holy Ghost without the aid of a human father.
   4. Both births brought great joy (e.g., the responses of Sarah and Mary).
   5. Both births provoked persecution – Isaac at the hands of Ishmael and Christ at the hands of Herod.
2. How it pictures salvation.
   1. It pictures salvation in the fact it was the second birth in Abraham’s family and the one God blessed. In the Old Testament we often see the picture of God rejecting the firstborn and accepting the second born (e.g., Jacob instead of Esau, Ephraim instead of Manasseh) In Ishmael we have a picture of the natural man. We all have the Ishmael birth – we are born into this world physically and inheriting the sin nature from Adam. Ishmael was “born of the flesh” whereas Isaac was “born of the Spirit”. We need the second birth symbolised in Isaac. Jesus said John 3:5-7 “Jesus answered, Verily, verily, I say unto thee, Except a man be born of water and of the Spirit, he cannot enter into the kingdom of God. That which is born of the flesh is flesh; and that which is born of the Spirit is spirit. Marvel not that I said unto thee, Ye must be born again.”
   2. It pictures salvation in that it was a miraculous birth. The new birth is a miracle God performs by His Holy Spirit when we repent and come to God by faith through Christ Jesus. John 3:6 “That which is born of the flesh is flesh; and that which is born of the Spirit is spirit.”
   3. It pictures salvation in that a deadness was present. Abraham was considered dead in his ability to father children and Sarah was considered dead in her ability to conceive and bear children (Rom. 4:19). God brought life out of death. Before salvation we are dead in trespasses and sins but God makes us alive again through salvation. Ephesians 2:1 “And you hath he quickened, who were dead in trespasses and sins;”
   4. It pictures salvation in that it was the fruit and reward of faith. Ishmael was a child of the flesh; the best Abraham and Sarah could produce but God did not accept even their best- and well- intentioned efforts. Isaac was a child of faith and something only God could do by His power. Salvation is only by “grace through faith” (Eph. 2:8-9).
   5. It pictures salvation in that a new creature was produced. God did not reform Ishmael but provided Isaac, an entirely new creature. When we get saved, we are made new creatures in Christ (2 Cor. 5:17).
   6. It pictures salvation in that Isaac gained a new inheritance by virtue of his birth. He became his Father’s heir. As believers we are now “heirs of God”. “The Spirit itself beareth witness with our spirit, that we are the children of God: And if children, then heirs; heirs of God, and joint-heirs with Christ; if so be that we suffer with him, that we may be also glorified together.” (Rom. 8:16-17) The Apostle Peter reminds us of our inheritance.

The Mandate At His Birth (Vs. 3-4)

The obedience of Abraham is again highlighted at the birth of Isaac. In fact, while Abraham had some downfalls and was far from perfect, a humble spirit of submission to God and His will characterised his whole life. While Abraham made some unwise choices, we don’t see Him rebelling against God’s commands. At the birth of Isaac, Abraham obeyed in:

The Naming of the Child (Vs. 3)

1. God had commanded Abraham about the name for the child in Gen. 17:19 “And God said, Sarah thy wife shall bear thee a son indeed; and thou shalt call his name Isaac:”
2. On a simple level, parents can learn from this that it is wise to seek God’s leading on the naming of their children.
3. We are reminded that God’s blessings come with responsibilities. Children are a blessing but they are also come with responsibilities. There are commands God has for us as parents relating to how we are to raise our children and it is so important that we are obedient to raise our children God’s way. Happy the child who is born into a Christian home where the parents are submitted to God and His Word.

The Circumcising of the Child (Vs. 4)

1. Circumcision is not binding on the New Testament believer but again the principle of Abraham’s obedience is highlighted – “as God had commanded him.”
2. The truth of God’s statement of confidence in Abraham’s character as a father is demonstrated upon the birth of Isaac. Genesis 18:19 “For I know him, that he will command his children and his household after him, and they shall keep the way of the LORD, to do justice and judgment; that the LORD may bring upon Abraham that which he hath spoken of him.”

The Marvel At His Birth (Vs. 6-7)

These verses record Sarah’s joyful response to Isaac’s birth.

The Source of Sarah’s Rejoicing (Vs. 6a)

1. Sarah’s first laugh was the laugh of unbelief (Gen. 18:12) but now her laugh is that of fulfilled hope. The laughter of the world is hollow and empty – “For as the crackling of thorns under a pot, so is the laughter of the fool: this also is vanity.” (Ecc. 7:6) The laughter of the believer is the fruit of genuine joy on account of God’s goodness and grace.
2. Sarah’s example should encourage you that God is able to take you from the laughter of doubt into faith and the confident expectation in the promises of God and then to the laughter of joy as you witness God’s faithfulness in keeping His Word.
3. Ishmael, the fruit of Abraham and Sarah’s own efforts brought nothing but pain and sorrow but Isaac, the fruit of God’s miraculous power brought joy and blessing. Prov. 10:22 “The blessing of the LORD, it maketh rich, and he addeth no sorrow with it.” Wiersbe writes, “Isaac pictures the child of God not only in his birth but also in the joy that he brought. There is joy in heaven each time there is a miraculous birth of a sinner into the family of God. Nowhere do we read that Ishmael caused great joy in Abraham’s home. Abraham loved his son and wanted the best for him (Gen. 17:18). From before his birth, Ishmael was a source of painful trouble (Gen. 16); and after he matured, he caused even greater conflict in the family (21:9). The old nature is not able to produce the fruit of the Spirit, no matter how hard it tries.”

The Sharing in Sarah’s Rejoicing (Vs. 6b)

1. Sarah anticipated that others would join in her laughter as they heard of what God had done. This speaks of the theme of testimony. Our joy is a part of our testimony as believers before the unsaved. Psalm 40:3 “And he hath put a new song in my mouth, even praise unto our God: many shall see it, and fear, and shall trust in the LORD.”
2. On a practical level, do you have the capacity to rejoice with others when God blesses them? This is also a test of Christian maturity.

The Song of Sarah’s Rejoicing (Vs. 7)

1. Some suggest that Sarah’s words here were a song. We don’t know for sure but whatever the case maybe we can certainly say that songs of joy are the believer’s response to the mighty workings of God.
2. Psalm 100:1-5 A Psalm of praise. “Make a joyful noise unto the LORD, all ye lands. (2) Serve the LORD with gladness: come before his presence with singing. (3) Know ye that the LORD he is God: it is he that hath made us, and not we ourselves; we are his people, and the sheep of his pasture. (4) Enter into his gates with thanksgiving, and into his courts with praise: be thankful unto him, and bless his name. (5) For the LORD is good; his mercy is everlasting; and his truth endureth to all generations.”

Conclusion

Have you experienced the second birth?

Are you waiting on the Lord for the fulfillment of His promises or are you tempted to take things into your own hands?

Do you have total and complete trust in God’s Perfect Word?

Are you being a good testimony by rejoicing in the Lord?

Sermon 39 of 80 in Genesis Series