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Fear and Faith | Genesis 20-21

As preached by Timothy O'Day.

"In these chapters, you can see that sinful fear would destroy you, but God graciously and patiently overcomes it."

1) He preserves through sin.

2) He prunes adversaries to faith.

3) He provides in order to strengthen faith.

Fear and Faith

Genesis 20-21

September 17, 2023

Have you ever laid awake at night playing the “what if…” game?

• What if I lose my job?

• What if I don’t pay that bill on time?

• What if the test results come back positive?

• What if that creak isn’t just the house settling?

• What if this person rejects me?

• What if I don’t get the job?

• What if I am not good enough to keep the job?

• What if she finds out?

• What if he never changes?

• What if, what if, what if…

There are two versions of this game. One version calls for you to simply cower in the thought of “what if,” with a growing knot in your chest. The other version calls for you to make constant plans for each contingency. “If this happens, then that,” and “if that happens, then this…”

If you are not aware, this is not a good game to play. Not only is it bad for you, it dishonors the Lord. While troubles are inevitable, sinful worry is a choice. And, if you make the choice enough, it will become a habit. This habit can be so well practiced that it doesn’t even feel like a choice. It feels more like a natural reflex which leaves you saying, “I can’t help it.”

As we consider this, it helps make sense of what we encounter here in Genesis 20. In this chapter, Abraham goes to a new territory and, when there, does exactly what he did in Genesis 12 when he went to the new territory of Egypt: he tells people that Sarah is his sister instead of saying that she is his wife.

Upon first reading this, you might find it a little ridiculous. You might want to yell out, “come on Abraham! Isn’t it obvious that God is faithful and that you don’t need to fear man like you do?” And if that is your response, I want you to stop for a moment and consider what would happen if suddenly this screen behind me started running video of all the times you were caught up in fear. And then next would play all the ways in which God had shown you kindness and faithfulness. Imagining that, doesn’t Abraham make a little more sense to you? You have more in common with him than you might at first think.

Like water, your thoughts will travel the path of least resistance. And your actions make grooves in your heart that will direct the flow of your thoughts. Put that way, change might feel impossible. But God is in the business of making new creation. In Genesis 20-21, you get a first row seat to how God addresses fear in his people and makes them new. In these chapters, you can see that sinful fear would destroy you, but God graciously and patiently overcomes it.

Let’s walk through these chapters and see how that is the case.

1. He preserves through sin

In Genesis 20, we see that Abraham, like he did in Genesis 12, travels to a new place and is overcome with fear that he will be killed because of Sarah. Like in Genesis 12, he asks Sarah to tell people that she is his sister (a half-truth masquerading as the full truth, making it a lie). If you recall, when we were in Genesis 12 we talked about the logic of fear and it worked like this:

Sarah is beautiful


Someone will desire her


Since I am her husband, they will kill me to get to her


So I need to lie in order to stay alive

But what does that equation miss? God’s promise to Abraham that God would use him to bless the whole world by giving him a son through Sarah. Fear leads us to make predictions that we then use to forget and mitigate God’s promises.

Have you ever done that?

Abraham lies because, as you see in verse 11, he thought there was no fear of God among these people. Which is another way of saying, “God you are only as powerful as people let you be.” The fear that Abraham is displaying is fear that forgets God. And in forgetting God, Abraham compromises his wife and the means that God is going to use to bring about his promise.

The Lord Preserves His Promise

But the Lord preserves his promise despite Abraham’s sin. In fact, the Lord preserves Abraham despite his sin. God’s promises are sure not because man is faithful but because he is faithful. How does God preserve this line of promise? He does three things.

First, God confronts Abimelech. In a dream, he calls out Abimelech and says to him, “you’re a dead man.” This is a confrontation that brings sin to Abimelech’s attention. The warning “you’re a dead man” is the kind of warning that would get anyone’s attention. It is, in a way, what conviction feels like. Conviction is the feeling that you are guilty and will be held accountable.

Second, God constrained Abimelech. After the initial confrontation over the fact that he took Sarah, Abimelech pleads innocence: he didn’t know that Sarah was Abraham’s wife. After all, Abraham said that Sarah was his sister. So, yes, Abimelech was covetous, but it was a noble kind of covetousness (We always have a way of making ourselves look good, don’t we?). Not only this, but Abimelech says that he has not yet had relations with her (verse 4)

What is God’s response? He knows that Abimelech did not knowing take another man’s wife, and it was God himself who kept Abimelech back from sleeping with Sarah. That is to say, God constrained him from sinning so that his promise would stand. “The king’s heart is a stream of water in the hand of the LORD; he turns it wherever he will” (Prov 21:1). God is sovereign over sin. God will not allow sin that will destroy the promises he has given to his people.

Third, God commands Abimelech to return Sarah to Abraham or die along with his whole house. This comes with a promise: if he reconciles with Abraham, then he will be reconciled to God.

The Lord is the hero in this incident, but Abimelech is our example to follow. While Abraham exemplifies sinful fear, Abimelech models godly fear. Upon hearing God’s word, he takes it with utmost seriousness. Verse 8 tells us that he rose early in the morning and did exactly what the Lord commanded him to do. That’s what godly fear looks like. Abimelech could have woken up in the morning and said, “what a wild dream!” He could have tried to play it off because he had a reputation to lose and, as we will see, livestock to lose. But he is preoccupied with what God has said more than anything else. Godly fear keeps his word central to our thinking and our circumstances secondary.

Who Are You Like?

Which fear feels more familiar to you? Godly fear that is preoccupied with what God has promised and what God has commanded? Or sinful fear that circumstances and the power of man cloud out the power and promise of God?

Christian, if your answer is sinful fear, then I don’t want you to miss the shocking reality revealed in this passage: your sinful fear does not negate God’s promise to keep you. God does not reject Abraham because of his fear because he promised to use him. Jesus says to you, Christian, that if you come to him then he will never cast you out. “All that the Father gives me will come to me, and whoever comes to me I will never cast out” (John 6:37). Do you find in yourself a pattern of fear and anxiety? You aren’t disqualified from God’s people. In fact, you fight right in. “If we are faithless, he remains faithful—for he cannot deny himself” (2 Tim 2:13).

Do you see Abraham’s status at the end of his chapter? He has sinned by forgetting God’s promise and trying to save his own skin by lying, but his status remains unchanged. He must pray for Abimelech in order for Abimelech and his household to be restored.

Is your sinful fear a problem? Yes. Does it disqualify you? No. God preserves you through your sin. But this doesn’t mean you should be okay with your sin. Instead, this should encourage you to expose your sinful fear to God whenever you feel it. Say, “Lord, I am afraid. Help me to know and believe what is true and to bring it to bear on this fear.” The graciousness of God to his own encourages you to make your sinful fear known rather than hiding it.

But that is speaking to the Christian. If you are not in Christ, meaning that you aren’t trusting him and you haven’t given your allegiance to him by faith, then your present situation is not good. You need to be confronted by God about your sin. Perhaps you’ve experienced that. Perhaps it is happening this morning. If God is exposing and convicting you of your sin, then you need to turn from justification and simply confess. Revelation 22:17, “The Spirit and the bride say, ‘Come.” And let the one who hears say, “come.” And let the one who is thirsty come; let the one who desires take the water of life without price.” Do you desire? Come and take Christ, the water of life. Come to Christ and you will be protected from the wrath that your sins deserve because Christ has borne that wrath already. Don’t delay. Rise up early and obey this gracious command to receive richly from Christ.

2. He Prunes Adversaries to Faith (21:1-21)

At many years for Abraham and Sarah, and many chapters for us, the moment has come: Isaac is born. While this momentous moment is captured in just a few verses, make sure you see the key words that should catch your eye.

“The Lord visited Sarah as he had said, and the LORD did to Sarah as he had promised(1).

“And Sarah conceived and bore Abraham a son in his old age at the time of which God had spoken to him(2).

“And Abraham circumcised his son Isaac when he was eight days old, as God had commanded him(4).

“And Sarah said, ‘God has made laughter for me” (6).

Do you see the emphasis? God has done it. God has kept his promise. What seems physically impossible has come about. It did not happen on the time frame that Abraham and Sarah may have expected, but it happened. It didn’t happen with the speed that Abraham and Sarah demanded, but it happened.

The Birth that Foreshadows THE BIRTH

The birth of Isaac is not the ultimate birth for which the world waits, but it does portend to it. You see this theme build throughout the rest of the Bible in which a woman, who you would not expect to have a child, is helped by God to have an important child. Here is Isaac, soon will come Esau and Jacob after a season of barrenness for Rebecca. Then will come Samuel born of the barren Hannah. Then there is the promise in Isaiah 7 of the most unlikely birth of all: “Behold, the virgin shall conceive and bear a son, and shall call his name Immanuel” (Isaiah 7:14). Immanuel meaning “God with us.” While Abraham and Sarah’s wait is over with the birth of Isaac, truly the wait does not end until the birth of Christ, who is born of a virgin and truly is God who has taken on flesh to dwell among us (Matthew 1; John 1).

After the birth of Christ, you find all who interact with him fall into one of two camps: those who kiss the Son, an act of allegiance, and find refuge in him (see Psalm 2). And those who plot in vain against him (Ps 2).

Danger to Faith Foreshadowed

Just as the birth of Isaac is both the means and the sign pointing forward to the ultimate hope of Christ, the disdain of Ishmael at the birth of Isaac exemplifies and points forward to despising God’s promise of salvation in Christ. As chapter 21 continues, you see in verse 8 that time flies by. Isaac grows and is weaned. Abraham throws a feast to celebrate. Then, in verse 9, you read “But Sarah saw the son of Hagar the Egyptian, whom she had borne to Abraham, laughing.” This word for laughter is the same as the laughter that defines Sarah, but even though the word is the same, the intent is clearly different. How do we know it is different?

First, Sarah sees it as different. She wants Hagar and Ishmael cast out after she sees this laughter (10). If the laughter was celebratory and true joy, like it was for Sarah, then it would be odd for Sarah to have such a reaction.

Second, as you read Genesis as a whole, you find that often times an older child hated the fact that a younger brother took preeminence over him. Cain killed Abel when God favored him more; Esau plans to kill Jacob after Jacob receives the birthrate and blessing over against him; Joseph’s brothers, as you will see, fake Joseph’s death and sell him into slavery because they are jealous of him.

Third, the New Testament witness of Galatians 4:21-31 verifies that Ishmael’s laughter falls into the category of persecution, not love. His laughter was, in effect, saying, “You will not inherit over me.”

The Problem Made Clear

It was not irate jealousy that led Sarah to call on Abraham to cast Ishmael out; it was faith in God’s promise. Abraham, though, was conflicted, as you see in verse 11, “on account of his son,” meaning Ishmael. He had listened to the voice of his wife once before, in Genesis 16, and that led to Abraham taking Hagar and begetting Ishmael. He is hesitant to listen again, which is why God speaks to him in verses 12-13, saying “Be not displeased because of the boy and because of your slave woman. Whatever Sarah says to you, do as she tells you, for through Isaac shall your offspring be named. And I will make a nation of the son of the slave woman also, because he is your offspring.”

What was the problem? Abraham loved Ishmael, but that wasn’t his only hesitation. You see in God’s solution that there were two problems: God promises that Ishmael will prosper, which handles the loving concern that Abraham had for him (and, as verses 15-21 show, he did care for them). But he also stresses at the end of verse 12 that “through Isaac shall your offspring be named.” Why stress that? Because Abraham needs to stop hedging his bets. In Genesis 17:18, when God gave the clarifying promise that Abraham would have a son by Sarah and this son would be the child of the covenant promise, he cried out “Oh that Ishmael might live before you!” He didn’t want to wait anymore. Isaac has arrived, but wouldn’t it be wise to have a backup plan? Maybe Ishmael?

God’s response is a resounding, “No.” He wants Abraham to put all of his hope into Isaac as the promised child.

God’s Radical Call

We are constantly tempted to hedge our bets. In Christianity, you are tempted to do this through works. That’s exactly what Ishmael represents for Abraham: his human attempt to bring about God’s promise. By letting him God, he is truly saying, “Only God can give me what he has promised. I cannot do it.”

What do you need to let go in order to say to God, “I know I can’t bring about my own salvation?” To say, “I know that eternal life, eternal joy, is something that you and only you can give?” In other words, what do you need to let go? The story of the rich ruler from Luke 18 may help you discern what that is. In Luke 18, Jesus has an encounter with a rich man who comes and asks him what he needs to do in order to have eternal life. Jesus says, “you know the commandments.” And the man replies, “I’ve kept them from my youth.” After hearing this, Jesus says to him, “one thing you lack: sell all that you have, give it to the poor, and come, follow me.” After hearing Jesus say this, the man departed in sorrow, because he had great possessions.

Why did Jesus tell him to sell all that he had and to give it to the poor? He didn’t and doesn’t call all of his disciples to do this, so why this man? It is because it was what that man trust and desired above everything else. When push came to shove, it was the treasure he was not willing to release. It made him feel safe, important, and happy.

What is that for you? Whatever it is, it cannot deliver it to you. Eternal life and eternal joy are in Christ and Christ alone. Drop all else and cling to him.

3. He provides in order to strengthen faith

At the end of chapter 21, it is helpful for us to remember what Abraham was promised and what he has now received. Back in Genesis 12, God promised Abraham descendants, blessing, a great name, and the land of Canaan. From Genesis 12 on, we have read how God has given him all of these things, including Isaac from the once barren womb of Sarah. Now, in 21:22-24, Abimelech and Phicol, his commander, verify another promise kept by God to Abraham: a great name. Abraham has become so influential and prosperous that the king of the land wants to make a treaty of security with him. This is a mutual promise that they will not cause each other harm.

In light of all that God has done for him, we see in these verses a more mature and trusting Abraham. God has preserved him and pruned him of obstacles to trusting him alone. What is the result? He no longer fears Abimelech. We see this in the fact that after agreeing to make this treaty, Abraham immediately reproves Abimelech for a well that his men had seized from Abraham’s men. After Abimelech claims ignorance (a common excuse it seems with him), Abraham, after making the covenant, sets aside 7 ewe lambs. This is not part of the covenant ceremony, which is shown by the fact that Abimelech doesn’t know what is going on. The lambs are a gift from Abraham to his new covenant partner which obligate him to act as a witness that the well belongs to him. Abraham is, then, immediately testing the strength of this covenant right after making it. This is a bold move showing that Abraham believes God will give him favor to secure a spot in the land that he has promised to him.

And it works.

After this, Abraham plants a Tamarisk tree and called on the name of the LORD, the Everlasting God. His sinful fear has given way to confident, joyful, worship because his faith is strengthened through God’s faithfulness to him.

What If God’s Promises Are True?

In effect, Abraham was playing the “What if” Game in these verses. But he played the “What if” game of faith and not of fear. He asked, “what if God’s promises to give me this land are true? What if God really is set on blessing me and making me a blessing?”

The result of this game is not crippling faith, but joyful worship.

You, too, can play the what if game of faith.

• What if my sins really are totally forgiven in Christ? I can be myself and not hide anymore.

• What if nothing can separate me from the love of God in Christ Jesus my Lord? My best days are yet to come.

• What if eternal life and eternal joy are found in Christ alone? I do not need to fret over earthly treasure or earthly status!

• What if I really can come to Christ and never be cast out? I have a security that no on in this world can understand.

Grab any promise given in Christ Jesus and ask “what if…” and marvel at the glories that await us because of his goodness and kindness toward us. Amen. Let’s pray.


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