Latest / Reformed Thinking / “No, But Sarah”: Covenant Promise, Divine Election, and the Naming of Isaac (Genesis 17:15–22)
Transcript
- 0:00Welcome back to Reform Thinking. If you're looking for a way to
- 0:03get right to the core of God's redemptive work, I mean how he
- 0:07actually deals with our human strategies and why His promises
- 0:10are always so specific, then you are in the right place.
- 0:14We are doing a deep dive today, getting into one of the most
- 0:16theologically packed and I think personally revealing passages in
- 0:20the entire Old Testament. Our mission today is a close
- 0:22look at Genesis 17, and we're zeroing in on verses 15 through
- 0:2522. We've brought together a number
- 0:27of sources, historical, linguistic, systematic, to
- 0:30really get at this critical tension that's happening right
- 0:33there in Abraham's tent. And that tension is all about
- 0:36human effort versus divine election.
- 0:38It's about our pragmatic substitutes versus the absolute
- 0:41certainty of miraculous promise. This section of the story is
- 0:45really where the covenant crisis in Abraham's household just
- 0:48comes to a head. For 13 years there was this this
- 0:51question just sort of hanging in the air.
- 0:52A huge question. Right, and that question was, is
- 0:55God going to fulfill his covenant with Abraham through
- 0:57the logical, you know, the ready made product of human thinking,
- 1:00this strong teenage son, Ishmael.
- 1:03The son who's right there, who he can see every day, is.
- 1:05The fulfilment going to come through something totally
- 1:07different, a specific, miraculous and frankly
- 1:11impossible seeming promise. The son who would be named
- 1:13Isaac. This text is a real hinge point.
- 1:17It forces us to face something essential about faith.
- 1:20So the core question we're looking at for you, the
- 1:22listener, is this. How does God's divine election
- 1:25just completely overturn every logical, natural, and, you know,
- 1:30seemingly successful plan that we can come up with?
- 1:32And they are often very successful plans by our
- 1:34standards. They are, this passage demands
- 1:36that we decide is our identity and so our hope for the future.
- 1:41Is it defined by what we can do, by our successful methods?
- 1:44Or is it defined only by the unshakable certainty of God's
- 1:47Word? Let's let's unpack this.
- 1:50To really feel the weight of that decision Abraham has to
- 1:52make, we have to start with the context.
- 1:54And the context is defined by 13 years of well of complete
- 1:57silence. That time gap is so easy to just
- 1:59read right over. Yeah, it's so easy, but think
- 2:02about the atmosphere in Abraham's camp.
- 2:04So you remember Genesis 16 gives us the birth of Ishmael, Abraham
- 2:09and Sarai. They got impatient.
- 2:11They decided in a moment of, let's call it faithless
- 2:13expediency, to step in and help God out by using Hagar.
- 2:17Right, the surrogate plan. The surrogate plan and the
- 2:20result was tangible. It was a living, breathing,
- 2:23strong, successful boy, Ishmael. It worked.
- 2:26For a human perspective, the plan worked.
- 2:27It absolutely worked. And then nothing after that
- 2:30birth. The text records no define
- 2:33communication, no dream, no vision, no new word from God for
- 2:37more than a decade, 13 years. Just try to imagine that length
- 2:40of time. Living with the results of your
- 2:42decision and just. Total quiet.
- 2:45And that deafening silence is so important because it allowed a
- 2:48certain kind of comfort to settle in.
- 2:50During that long period, Abraham fell into what our sources call
- 2:54a comfortable theological assumption.
- 2:56In his mind, the crisis was over.
- 2:58It was solved. He had produced an air.
- 3:00He had watched Ishmael grow from a baby into a strong young man,
- 3:04and he had poured all this parental affection and energy
- 3:06into him. Sure of.
- 3:07Course he had. He was convinced that the
- 3:09covenant path, OK, maybe it was messy at the start, but it was
- 3:12now secure. The working assumption was that
- 3:15God would just, well, he would bless this successful, visible,
- 3:20fleshly effort. And that's the human element.
- 3:23That's so relatable, isn't it? When you've put 13 years of your
- 3:26life and your resources into something that looks like it's
- 3:28working and have all the momentum, it feels totally wrong
- 3:32to just scrap it. It feels like throwing away a
- 3:33massive sunk cost. It is a massive sunk cost and
- 3:36the problem we see developing in Abraham's life during those
- 3:39years is what you could call Plan B religion.
- 3:42Plan B religion. I like that.
- 3:44It's not a formal system, it's a posture.
- 3:46It's the belief that we can rely on what's visible, what's
- 3:49present, what's achievable, the results of our own clever
- 3:52strategies. And then we turn around and ask
- 3:54God to, you know, rubber stamp our actions as His true will.
- 3:58Sort of retroactively seeking approval for what we've already
- 4:01done. That's it.
- 4:02Ishmael was the ultimate product of a human workaround.
- 4:05He was the best possible result of their fleshly effort, and for
- 4:09more than 10 years, Abraham had made his peace with that
- 4:12compromise, just assuming that God, being gracious, would
- 4:15endorse the best option on the table.
- 4:17You see this everywhere today. Everywhere in the church, Plan B
- 4:21religion shows up when we start prioritizing growth metrics.
- 4:24You know, attendance numbers, cultural relevance, all the
- 4:27visible successes over the harder, often much slower work
- 4:31of deep spiritual change through the simple means of grace.
- 4:34So if Abraham is operating under this assumption that Ishmael is
- 4:38the heir apparent, how does God break into that settled world?
- 4:43Well, when the almighty God El Shaddai finally does break the
- 4:46silence in Genesis 17, he doesn't show up to validate
- 4:50Abraham's pragmatic choices. He comes to shatter them
- 4:53completely. So it's a confrontation.
- 4:55It is a direct confrontation. He appears specifically to
- 4:58dismantle the idol of fleshly effort and pragmatism that had
- 5:02been sitting comfortably in Abraham's tent for over a
- 5:04decade. The revelation we get in verses
- 5:0615 to 22 is a theological shock to the system of natural human
- 5:11reason. God announces the covenant will
- 5:14not flow through the vitality of Ishmael the strong teenage son,
- 5:19but through the dead and fertile womb of a 90 year old woman.
- 5:22The exact opposite of what seems logical.
- 5:24The complete opposite, and that contrast is what drives this
- 5:27whole text. The central idea is crystal
- 5:30clear. True faith, covenantal faith, it
- 5:33doesn't work by asking God to ratify our successful works of
- 5:36the flesh, right? True faith waits, often with a
- 5:39kind of trembling joy and shock, for the impossible fruit of the
- 5:42Spirit, which comes only by divine intervention, the silence
- 5:46of God. In those thirteen years, it
- 5:48wasn't God's consent to Abraham's plan.
- 5:50It was a necessary preparation period, allowing that idol of
- 5:53Ishmael to get solidified just so God could display His
- 5:56sovereign miraculous grace in tearing it down.
- 5:59I think the application there for anyone listening is it's
- 6:02incredibly challenging because we all have our Ishmaels.
- 6:05We all have those successful strategies or visible
- 6:07accomplishments. Maybe it's a business you built,
- 6:09a ministry structure, a system of personal discipline that we
- 6:12are proud of. And we're convinced that God
- 6:15must use these things to fulfill His promises in our lives.
- 6:18Exactly. We sort of project our own
- 6:20desire for efficiency onto God. We do.
- 6:22We think, look, I've done the heavy lifting.
- 6:24God now just come and bless the work of my hands.
- 6:27But this text is insisting that we identify those Ishmaels, the
- 6:31very best things we've produced with our own ingenuity, and ask
- 6:35ourselves if we're secretly begging God to accept them as
- 6:38the answer instead of just dropping our methods and waiting
- 6:41for His promised miracle. So the call to let go of our
- 6:44successes in a way. It's a call to understand that
- 6:47God's covenantal path often requires the failure, or at
- 6:51least the theological invalidation, of what we see as
- 6:54our human success. That's a powerful point about
- 6:57the weight of time. 13 years of investing in Ishmael made that
- 7:00human plan feel solid, reliable, almost sacred.
- 7:04To take that apart, it will require a truly sovereign act,
- 7:07and the narrative shifts focus completely in verses 15 and 16
- 7:11to do just that. The whole first part of Genesis
- 7:1417 was about establishing circumcision as the sign of the
- 7:18covenant in the flesh of the male.
- 7:20But then God uses this really forceful grammatical break to
- 7:24pivot directly to the woman. Yeah, to Sarah.
- 7:27To Sarah, our sources pointed out this fascinating linguistic
- 7:30detail. The Hebrew phrase As for Sarai,
- 7:33your wife, uses what's called a wah disjunctive.
- 7:36It's basically a purposeful jolt in the story, signaling that God
- 7:40is introducing a new, highly focused subject.
- 7:43It's almost like God is saying stop now.
- 7:45Listen very carefully about Sarai.
- 7:47It's the literary version of a drum roll before a huge
- 7:50announcement. And make sure Abraham can't just
- 7:52treat this as a side note. This is the main event now.
- 7:54It is. And why this big transition?
- 7:57It's to show that the covenant of grace isn't just an external
- 7:59physical thing. You know, the man circumcising
- 8:01his flesh, which Abraham could do.
- 8:03It's a divine creative act that has to include the previously
- 8:06barren and overlooked woman. God is grabbing Abraham's
- 8:08attention. He is.
- 8:10He's showing him that while circumcision is the sign of the
- 8:12covenant, the source of the covenant, life is going to be
- 8:15entirely miraculous, and it's tied directly to Sarah's
- 8:18destiny. And what comes next is just a
- 8:21sovereign redefinition of reality.
- 8:23God has just, you know, acknowledged Abraham's current
- 8:25situation. He speaks what is impossible
- 8:27into what must become certain, and that redefinition starts
- 8:31with her identity. It's her name.
- 8:32With her name we see the change. You shall not call her name
- 8:35Sarai, but Sarah shall be her name.
- 8:39To get the weight of this we have to look at the Hebrew.
- 8:41Both names come from the roots SAR, which means Prince or
- 8:45ruler. OK, the original name Sarai
- 8:48probably had a suffix that meant my Princess.
- 8:51Our sources suggest this points to a restricted dominion.
- 8:54She was a Princess, but defined by her relationship to Abraham.
- 8:58She was his Princess. So her status is confined to
- 9:01Abraham's world honored, yes, but still defined by a human
- 9:04relationship. Exactly limited to the 10th, the
- 9:07domestic sphere. Her rule was personal within the
- 9:10household, but the new name Sarah drops that restrictive my
- 9:15and uses the feminine absolute form.
- 9:18She becomes simply Princess. Not my Princess, but the
- 9:21Princess. Universal.
- 9:23It signifies this massive shift in her status.
- 9:26She goes from a domestic role to a covenantal office.
- 9:29God elevates her to become a mother of nations.
- 9:31He gives her a title that has nothing to do with her
- 9:33biological reality at that moment.
- 9:36This act of naming, this defining of destiny separate
- 9:40from current reality, it lines up so powerfully with the
- 9:43Reformed understanding of God's decree in Providence.
- 9:46Our confessional documents talk about how God sovereignly
- 9:49assigns names, and in doing so He defines the essence and
- 9:52future of His elect, completely independent of their natural
- 9:55abilities or what their current life looks like.
- 9:57He's naming what isn't yet there and treating it as a certainty.
- 10:00He's authoring her destiny. He is, and it's fascinating
- 10:04because the naming itself is an act of creation.
- 10:07Abraham and Sarah tried to create an heir through
- 10:10biological effort with Ishmael. God's response is to recreate
- 10:13the parents first. He renames Abraham to Abraham
- 10:16and now Soraya to Sarah. It's a signal that fulfilling
- 10:19the promise doesn't require better human effort.
- 10:22It requires divine authorship of the people involved.
- 10:25That's right, And the text just hammers this idea of divine
- 10:28authorship or monarchism with the repeated use of the first
- 10:32person singular in verse 16. The promises are all on God's
- 10:35shoulders. He says I will bless her and I
- 10:37will give you a son, and then again I will bless her.
- 10:40The burden of performance is entirely on the Almighty.
- 10:43There's no command here for Sarah to try to conceive, no
- 10:46instruction for Abraham to do anything different.
- 10:48There's only the declaration that God will create life.
- 10:51And that language is such a deliberate, forceful closing of
- 10:55the Hagar and Ishmael chapter. It is by saying I will give you
- 10:58a son by her. God explicitly slams the door on
- 11:01that whole cultural pragmatism of surrogacy.
- 11:04The text forces Abraham and it forces us to look away from the
- 11:08strong, present teenage Ishmael and look toward the 90 year old
- 11:11biologically dead womb of his wife.
- 11:14The emphasis is on the specificity.
- 11:16Not just any sun will do. The covenant requires a specific
- 11:19son from a specific line through a specific miraculous act that
- 11:22involves Sarah. And theologically, this just
- 11:25confronts the air of naturalism in a huge way from a purely
- 11:28human biological viewpoint. Sarah's is a dead end, but God
- 11:31connects her new name to the royal promise that kings of
- 11:34people shall be of her. So it's looking way ahead.
- 11:36Way ahead to the Davidic monarchy and of course, to
- 11:39Christ himself. The promise isn't just for a
- 11:41baby, it's for a divinely authored royal line that starts
- 11:44with a woman who is naturally unable to have a child.
- 11:47Our identity isn't defined by our past failures or our
- 11:50biological limits, but by the new name God speaks over us and
- 11:53the decree He establishes. This whole section is a master
- 11:57class in God's creative monarchistic decree.
- 12:00And that Word of God spoken with such certainty and carrying the
- 12:04full weight of the Almighty, it immediately collides with the
- 12:07logic of the flesh. And that collision results in
- 12:10Abraham's iconic but very complex reaction, the laughter.
- 12:14The laughter. Verse 17 documents this classic
- 12:17theological tension. The text says Abraham's response
- 12:20was bifurcated. It was two things at once.
- 12:24Then Abraham fell on his face and laughed.
- 12:26We really can't understand this without looking at both parts.
- 12:29The action and the reaction. Right.
- 12:30First, the posture falling on his face.
- 12:34This is an act of submission. It's reverence.
- 12:36It is a physical act of worship. Before El Shaddai, Abraham is
- 12:40acknowledging the sheer sovereignty and holiness of the
- 12:42one speaking to him. That is the correct theological
- 12:45response to God. That submission is so important
- 12:47because it sets the context. He isn't just laughing it off,
- 12:50he's submitting to the authority of the one speaking.
- 12:52Precisely. But at the same he laughs.
- 12:55And this laughter is Yitzhak in Hebrew, which of course becomes
- 12:58the name of the promised son, Isaac.
- 13:01Now, how we interpret this laughter is critical.
- 13:03Because it could be seen as doubt it.
- 13:05Could, and our sources are very careful to distinguish this from
- 13:08the cynical, faithless mockery of Sarah that we see later in
- 13:12Genesis 18. The Apostle Paul actually gives
- 13:14us the interpretive key in Romans 4 where he says that
- 13:17Abraham, looking at his own body, and Sarah Baroness, did
- 13:20not waver an unbelief, but grew strong in faith, giving glory to
- 13:24God, being fully assured that what God had promised, he was
- 13:27also able to perform. So Paul reads it as an act of
- 13:30faith. He does.
- 13:32Therefore the consensus is that Abraham's laughter here isn't
- 13:35the laughter of cynical doubt. It's the startled, joyful shock
- 13:38of a finite mind trying to get its head around the sheer
- 13:41impossibility, the absurdity, of infinite grace.
- 13:43It's the laughter of holy amazement, a response that's
- 13:46almost involuntary because the promise is so good, so specific,
- 13:50and so far beyond any natural expectation.
- 13:52That distinction between the laughter of holy astonishment
- 13:55and the laughter of cynical doubt is key.
- 13:58But then you look at the very next few phrases where he's
- 14:00speaking his internal thoughts, and doesn't that suggest that
- 14:04maybe his amazement was mixed with some very real logical
- 14:08doubt? He submits, he lasts in shock.
- 14:11But then his internal monologue reveals this huge conflict
- 14:14between human reason and the divine promise.
- 14:16That's the critical tension this passage capture so perfectly.
- 14:20His internal dialogue immediately shifts to a rational
- 14:23calculation. He asks himself, will a child be
- 14:26born to a man 100 years old? And will Sarah, who is 90 years
- 14:30old, bear a child? He's doing the math.
- 14:32He's doing the math. He's assessing the biological
- 14:34data. He's looking at the medical
- 14:35reality of his 100 year old body and Sarah's 90 basically dead
- 14:40reproductive system. A biological fact the New
- 14:42Testament brings up again. And his reasoning is sound from
- 14:45a naturalistic standpoint. It's completely sound.
- 14:48If you take God out of the equation.
- 14:49The promise is absurd. It's impossible.
- 14:52And this internal struggle exposes a common sin of
- 14:55unbelief, measuring God by our human limitations.
- 14:59Abraham is being forced to decide right then and there
- 15:01whether his ultimate reality is defined by his geriatric
- 15:04condition and the observable facts, or by the authoritative,
- 15:08impossible Word of God, El Shaddai.
- 15:11And that moment of logical, natural pushback then comes out
- 15:14in his external plea in verse 18.
- 15:17This is his counter proposal. It is.
- 15:19Oh, that Ishmael might live before you.
- 15:21Yeah. This is the quintessential
- 15:22expression of the logic of the flesh after you've just been hit
- 15:25with a promise that's too big to believe.
- 15:27To live before God in this context means to enjoy
- 15:30covenantal favor and status. It means to be recognized as the
- 15:34legitimate heir through whom the promise will flow.
- 15:36So he's asking God to switch airs.
- 15:38He is, in effect, asking God to validate his own successful,
- 15:42functional, pragmatic solution. Ishmael is the bird in the hand.
- 15:46He's the tangible, visible success he has invested in and
- 15:50loved for 13 years. He's strong, He's available, and
- 15:53most of all, he is present. Abraham is asking God to
- 15:56downgrade his promise from a miraculous act to a simple
- 16:00ratification of human success. That plea just encapsulates the
- 16:03sin of pragmatism perfectly. It's the preference for the
- 16:06visible result over the supernatural process.
- 16:09It is, and the application for us today is so powerful.
- 16:12Just as Abraham preferred the visible, tangible results of the
- 16:16bondwoman's son, the efficient, established, growing option, the
- 16:20modern church so often gravitates toward the visible,
- 16:22measurable success of marketing, slick programming or
- 16:25sociological maneuvers. We create our own Ishmaels.
- 16:28We do. We create our own successful
- 16:30methods and strategies, and then we try to compel God to
- 16:32establish his covenant on them, rather than waiting for the
- 16:35slower, invisible, supernatural work that's accomplished only by
- 16:38the Word and the Spirit. We try to secure the divine
- 16:41promise through human strategy instead of waiting on divine
- 16:44appointment. It's that constant temptation to
- 16:47equate effectiveness with faithfulness.
- 16:50If something is working efficiently by our human
- 16:52standards, we just assume it must be God's appointed way.
- 16:55That's it. And if you look at the
- 16:57theological structure here, Ishmael was the product of
- 17:01Abraham's human strength and physical ability.
- 17:03He was a work of the flesh, born according to nature.
- 17:07Isaac, on the other hand, would be born exclusively through
- 17:09promise, contrary to nature, purely by God's creative action.
- 17:13So by clinging to Ishmael, Abraham is trying to secure a
- 17:16covenant where human effort gets to share in the glory.
- 17:19He's trying to create a partnership, but God's covenant
- 17:22is monarchistic. It relies only on his action, so
- 17:25that all the glory belongs to Him.
- 17:27And This is why the New Testament authors lean so
- 17:30heavily on this story. So heavily, as Paul argues in
- 17:33Galatians 4, this is about more than family dynamics.
- 17:35This is the core battle between two systems of salvation.
- 17:38Ishmael represents the covenant of works and slavery, the
- 17:42attempt to gain status through what you can produce.
- 17:44Sarah and Isaac represent the covenant of grace and freedom
- 17:47status received only through the promise of God.
- 17:50So Abraham wants God to accept his best efforts.
- 17:53But God requires Abraham to set his efforts aside completely and
- 17:56just receive a miracle. So in that moment, Abraham tries
- 17:59to negotiate, offering up his pragmatic substitute.
- 18:03God's response just comes down like a hammer establishing the
- 18:06covenant boundary. Oh, absolutely.
- 18:08God's answer to the plea, Oh, that Ishmael might live before
- 18:11you is so forceful and absolute. Verse 19 starts with no, but
- 18:16Sarah, your wife will bear you a son.
- 18:18That Hebrew particle use there a it's critical.
- 18:22It acts like a divine stop sign. It's an emphatic no that just
- 18:26rejects Abraham's attempt to negotiate or change the terms of
- 18:29the deal. It is not a gentle correction.
- 18:31It's an immediate, authoritative assertion.
- 18:33God is saying, I understand your logic, Abraham, but you are not
- 18:37the author of this covenant. My word stands.
- 18:39And that divine No is so key because it's safeguards the very
- 18:42nature of sola gratia grace alert alone.
- 18:45If God had accepted Ishmael as the main heir, the covenant
- 18:48would have been grounded at least partly in human capability
- 18:51or foresight or physical strength.
- 18:52Right. It would have been a joint
- 18:53venture. A joint venture.
- 18:56By insisting on Isaac, God makes sure the covenant serves as a
- 18:59perpetual witness to his ability to bring life from death.
- 19:02Election. The promise is based only on
- 19:05God's sovereign choice, not on Abraham's selection or his human
- 19:09effort. And then he immediately
- 19:10solidifies it. He does.
- 19:12He moves right to the naming of the child.
- 19:15You shall call his name Isaac, which means he laughs.
- 19:18The name does more than just identify the boy.
- 19:20It can is the absurdity that is now turning into covenant joy.
- 19:23So the name itself is a memorial.
- 19:25It is. It's a perpetual memorial.
- 19:27Every time someone says the name Isaac, it's supposed to call
- 19:29back this moment, the moment the old patriarch realized that
- 19:33salvation belongs completely to the Lord, not to human strength
- 19:36or planning. The name is a doctrine in
- 19:38itself. God fulfills His promise in ways
- 19:41that shock and delight us, showing His unmerited favor.
- 19:44And that name? Isaac.
- 19:46It functions as such a clear type for the ultimate son for
- 19:49Christ. Isaac is the unique, beloved
- 19:52elected son, the only heir born miraculously to bring joy to the
- 19:56world. The firm rejection of Ishmael as
- 19:59the covenant head preserves that typology of the true Son, who is
- 20:03later described as being born not of blood, nor of the will of
- 20:06the flesh, nor of the will of man, but of God.
- 20:10Isaac's birth is the template. It's the template for the whole
- 20:13spiritual lineage. But the text also shows us the
- 20:15expansive nature of God's justice and goodness, even when
- 20:19he's rejecting something. This is where we see a really
- 20:22crucial systematic distinction between common grace and special
- 20:25grace. Yes, Abraham's prayer for
- 20:27Ishmael is not ignored. It isn't ignored, it's genuinely
- 20:30heard, but the way it's fulfilled is specific and
- 20:32limited. When God talks about Ishmael, he
- 20:35says, As for Ishmael, I have heard you.
- 20:37Behold, I will bless him and will make him fruitful, and will
- 20:39multiply him exceedingly, and this is a big promise.
- 20:42A very big promise. Ishmael gets temporal
- 20:45prosperity. He becomes the foundation of a
- 20:47great nation. He's the father to 12, Princess.
- 20:49This is the realm of common grace, God's universal goodness,
- 20:53providing political power, physical sustenance, cultural
- 20:56influence to all humanity, even those outside the specific
- 21:00redemptive line. And it's so important to just
- 21:02sit with that contrast for a second.
- 21:04God is good to Ishmael. He gives him success, growth,
- 21:07visibility. History confirms the reality of
- 21:10Ishmael's descendants being fruitful, but look at the
- 21:13difference in language. God says I will bless him.
- 21:17That's extensive, but it's temporal.
- 21:19But then the text immediately pivots with that sharp
- 21:22disjunction in verse 21. But my covenant I will establish
- 21:25with Isaac the Hebrew word Barrett, the covenant which
- 21:28contains in the messianic line reconciliation with God, eternal
- 21:31redemption. Yeah, that is exclusive.
- 21:33That contrast between I have blessed him for Ishmael and I
- 21:36will establish my covenant with Isaac is the theological
- 21:39backbone of this entire section. It gives us absolute redemptive
- 21:42clarity, affirms the principle that Paul will articulate later.
- 21:45Not all who are physically descended from Abraham are
- 21:48children of the promise. The promise of the saving
- 21:50covenant is defined not by genetics or natural success, but
- 21:54by God's specific election. And this specific definition of
- 21:57the redemptive channel, it just fundamentally refutes
- 22:01theological errors like universalism or pluralism.
- 22:05While God's goodness, his common grace to Ishmael is wide, his
- 22:10redemptive intimacy and salvific purpose, His special grace
- 22:14through Isaac are specific, singular, and directed entirely
- 22:18through his chosen channel. The fact that Ishmael gets a
- 22:21great blessing does not mean he receives the covenant
- 22:24inheritance. No, two different things.
- 22:26Two different things. And on top of that, God anchors
- 22:28this promise not just to a person, but to a specific
- 22:31historical calendar, He says, whom Sarah will bear to you at
- 22:34this season, next year. He defines the mode, the
- 22:37appointed time. That historical anchor is so
- 22:40vital it prevents any vague spiritualizing of the promise.
- 22:44God ties His word to a calendar so that Abraham's faith has to
- 22:47rest on a concrete, verifiable pledge, not just some general
- 22:51fuzzy optimism. If the promise was just
- 22:53eventually you'll have a son, it would be so much easier to fall
- 22:55back on Ishmael. But God demands that Abraham
- 22:58wait for a specific miracle at a specific date to establish the
- 23:02specific air. And this insistence on
- 23:04specificity really challenges is our modern idol of immediacy.
- 23:08We want the results now. God demands that we wait for his
- 23:12appointed time and that we wait for them through his appointed
- 23:15means. This verdict of rejection and
- 23:17election is, when it comes down to it, a profound pastoral
- 23:21comfort. It assures us that the security
- 23:24of the covenant doesn't rest on our fluctuating efforts are
- 23:27Ishmaels or on our moral resumes.
- 23:29God rejects our methods precisely to make sure that our
- 23:32inheritance rests entirely on His unchangeable choice and
- 23:35faithfulness. That's right, If it rested on
- 23:37Ishmael, the whole thing could be undone by human failure.
- 23:40But since it rests on Isaac, the impossible promise, it is
- 23:43secured by divine action alone. And this clarification, this
- 23:47divine decree, is given with a majestic finality that just
- 23:50demands an immediate response. It does.
- 23:52The narrative closes with when he finished talking with him,
- 23:55God went up from Abraham. The time for consultation, for
- 23:58debate, for negotiation. It's.
- 24:00Conversation is done. It's done.
- 24:02The silence returns. But it's not the empty,
- 24:05ambiguous silence of the last 13 years.
- 24:07It's now a silence that is pregnant with a specific,
- 24:10irrevocable promise. The fact that God went up from
- 24:13Abraham really underscores his sovereignty.
- 24:16He is the high and lofty one who comes down to speak grace and
- 24:19then ascends to govern history, leaving Abraham not with a
- 24:22lingering argument, but with an immediate duty.
- 24:25Circumcision. Circumcision, the decree stands.
- 24:28Abraham's proper response is submission and immediate action,
- 24:31which shows that the imperative of obedience is always grounded
- 24:34in the indicative of the Gospel. He circumcised Ishmael and the
- 24:38others in his households that very same day.
- 24:41And Isaac's very existence then becomes the enduring paradigm of
- 24:44grace for the rest of Scripture. His birth life from death.
- 24:47Like barrenness, it anticipates the much greater miracle of the
- 24:50new creation secured by Christ. Isaac is a covenant bearer whose
- 24:54entire life testifies that God brings strength from weakness
- 24:57and life from barrenness solely by promise.
- 24:59And this narrative is so far from being confined to the
- 25:02history of the patriarchs, it becomes the engine for
- 25:05foundational New Testament interpretation, showing us how
- 25:09redemption has always worked. That's so right.
- 25:12Paul uses the Isaac Ishmael example over and over again.
- 25:15He makes it the central pillar for defining who the true people
- 25:18of God actually are. Right in Romans 9.
- 25:21In Romans 9, Paul appeals directly to this distinction to
- 25:24show that covenant membership is determined by God's election,
- 25:27not by physical dissent or by adherence to the law.
- 25:31He explains that not all who are Israel according to the flesh
- 25:34are Israel according to the promise.
- 25:36The principle is clear. Only the children of promise,
- 25:39Isaac, not Ishmael, are counted as offspring in the redemptive
- 25:42sense. It's all about God's sovereign
- 25:44choice. It's entirely about God's
- 25:46sovereign choice according to the counsel of His will,
- 25:48irrespective of human works. If Abraham could have chosen
- 25:52Ishmael, we would have a different gospel.
- 25:54And then in Galatians 4, he pushes that typological
- 25:57connection even further, using Sarah and Hagar to contrast
- 26:01freedom and slavery. It's an analogy for the two ways
- 26:04people try to relate to God. It is Hagar and Ishmael
- 26:07represents slavery to the law, trying to gain righteousness and
- 26:11inheritance through works, through human strength.
- 26:14Paul says they are born according to the flesh.
- 26:17Sarah and Isaac represent freedom and grace being born
- 26:20through promise. And he applies that directly to
- 26:22the believers he's writing to. Directly, he says, believers
- 26:26today are identified with Isaac, those whose existence as God's
- 26:29people is owed entirely to God's divine miraculous initiative,
- 26:34not to their own effort or their pedigree.
- 26:36So when we try to secure our standing before God through our
- 26:39moral performance, our religious achievements, or our spiritual
- 26:43resume, our own Ishmaels, we're aligning ourselves with Hagar
- 26:46the slave woman. We are, but when we rely
- 26:49entirely on the promise of Christ, the true Son, we are
- 26:52aligning ourselves with Isaac, the child of the free woman.
- 26:55God rejected Abraham's methods precisely to secure our
- 26:57inheritance in his unchangeable choice.
- 27:00So if we pull all this together, what does this entire deep dive
- 27:03mean for us when we are faced with that daily pressure to
- 27:06perform, to plan, and to produce our own success?
- 27:09Well, I think the lesson is that distinction between our human
- 27:12pragmatism and God's divine specificity.
- 27:15God is generous to the Ishmaels of our lives.
- 27:17He grants blessing, fruitfulness, temporal success,
- 27:20showing his common grace. But his saving purpose, the
- 27:23Barrett, the eternal covenant, it moves only through his josen
- 27:27miraculous way, Isaac, and in the end, the true Son, Jesus
- 27:31Christ. We're called to trade that
- 27:33initial laughter of rational skepticism, the one that you
- 27:36know does the math and assesses the impossibility based on human
- 27:39limits, for the laughter of holy astonishment and faith, resting
- 27:43entirely in a salvation that is the Father's gift.
- 27:45We stopped trying to produce the promised result ourselves and
- 27:48instead wait upon the appointed Son.
- 27:50It's a constant realignment, isn't it?
- 27:52We have to stop trusting in the successful, visible things we've
- 27:55built. Instead, anchor our hope in the
- 27:57specific impossible promise of God.
- 27:59And let's just go back to the finality of that decree.
- 28:03Just as God ascended after securing the promise of the seed
- 28:05line through Isaac and setting the historical date for the
- 28:08miracle, Christ ascended after securing the eternal covenant
- 28:12through his blood. We are now the waiting people of
- 28:15God, living between the promise given and the consummation
- 28:18that's still to come. And this leaves us with a
- 28:21challenging thought as we close Look at your own life, your
- 28:24strategies, your investments, the things you're proud of.
- 28:26What current Plan B? What visible pragmatic effort
- 28:30are you tempted to trust in and rely on, rather than waiting for
- 28:33the return of the true Son, the specific elected seed, Jesus
- 28:36Christ, and resting entirely in his accomplished work?