He said, "I will surely return to you at this time next
year; and behold, Sarah your wife will have a son." And Sarah was
listening at the tent door, which was behind him. 11 Now Abraham
and Sarah were old, advanced in age; Sarah was past childbearing.
12 Sarah laughed to herself, saying, "After I have become old,
shall I have pleasure, my lord being old also?" 13 And the LORD
said to Abraham, "Why did Sarah laugh, saying, 'Shall I indeed bear
a child, when I am so old?' 14 Is anything too difficult for the
LORD? At the appointed time I will return to you, at this time next
year, and Sarah will have a son." 15 Sarah denied it however,
saying, "I did not laugh"; for she was afraid. And He said, "No,
but you did laugh."

God Requires the Impossible - the Gideon Venture

You recall from last week that God's purpose was to give the
Midianites into the hand of Gideon. Gideon had an army of 10,000
men. Arrayed against him were Midianites and Amalekites as numerous
as the sands on the seashore. So God did something very typical for
God and very atypical for man. "The LORD said to Gideon, 'The
people who are with you are too many for Me to give Midian into
their hands, for Israel would become boastful, saying, "My own
power has delivered me"'" (Judges 7:2).

It already looked impossible for Israel to defeat the Midianites
with only 10,000 men against so many. But God said, "Ten thousand
is too many." Why? Because my purpose is to display my glory, and
help you see how utterly dependent you are on sovereign grace.

This is the purpose of God in all that he does in creation and
redemption. God's purpose in all that he does is:

To magnify his sovereign grace And keep us in our humble
place.

And one of the central beliefs that we have as God's people is
that this is good news, not bad news. It is good news because God
himself, known to us in Jesus Christ, is more valuable and more
satisfying than anything we could ever be or do in our own power.
The most loving thing that God can do for us is to make himself
indispensable to us. The most loving thing God can do for us is not
to make much of us, but to work by his sovereign grace so that we
can enjoy making much of him forever. So, if he would love us, he
must exalt his sovereign grace and keep us in our humble, happy
place.

That's the point of the Gideon Venture. That is why God over and
over and over again in the Bible does things in a way that makes us
utterly dependent on God for what is humanly impossible - to
magnify his sovereign grace and keep us in our humble place.

God Does the Impossible - the Isaac Factor

This morning's message is simply to point to another Bible story
and how it illustrates this truth. It's the story of the birth of
Isaac, the son of Abraham and Sarah, the child of promise. Let's
get some of the details of the story in front of us.

According to Genesis 11:30, Abram's wife was barren even before
they came to the Promised Land. "Sarai was barren; she had no
child." This was not merely coincidental. It was planned by God. We
know this because in Genesis 16:2 Sarah said, "The LORD has
prevented me from bearing children." So God is putting in place
circumstances that will make the fulfillment of his promise humanly
impossible.

What promise? The promise that Abraham would have many offspring
and become a great nation. Genesis 12:2, "I will make you a great
nation, and I will bless you, and make your name great; and so you
shall be a blessing." That promise came after the knowledge that
Sarah was barren. Indeed, God had closed her womb, and then made
the promise. So now, if Abraham believes the promise, it will be a
believing not just in the ability of God to predict the future, but
in the power of God to create a future that is humanly
impossible.

This is what I call "The Isaac Factor": God's purpose to do what
is humanly impossible, so that we have to trust his power and
grace, and he gets the glory. But we do not naturally trust God so
easily. It goes against our fallen nature. Here's what usually
happens: When we meet a situation like this, we try to think of
ways that we can actually make it happen by ordinary human
means.

Let's watch this in Abraham's life. The first natural thought he
has is that God may fulfill his promise to make him a great nation
(Genesis 12:2) by raising up heirs to him through his slave,
Eliezer. God has to set Abraham straight here and make sure he sees
how impossible he really means the promise to be. Look at Genesis
15:2-4.

Abram said, "O Lord GOD, what will You give me, since I am
childless, and the heir of my house is Eliezer of Damascus?" And
Abram said, "Since You have given no offspring to me, one born in
my house is my heir." Then behold, the word of the LORD came to
him, saying, "This man will not be your heir; but one who will come
forth from your own body, he shall be your heir."

So God cuts off Abraham's escape. No, Abraham, my promise will
not be fulfilled in the humanly possible way of using your slave as
your legal heir. My way will be humanly impossible: You will become
a great nation through your own physical seed - your own biological
son.

God's Requirement for Us - Faith

What does God require from Abraham? He requires that Abraham
believe him, trust him. So God takes Abraham outside and says to
him in verse 5, "Now look toward the heavens, and count the stars,
if you are able to count them." And He said to him, "So shall your
descendants be." Then verse 6 says that "Abraham believed in the
LORD; and [God] reckoned it to him as righteousness." That's the
faith that corresponds to "The Isaac Factor".

But there is one more escape hatch from God's sovereign grace
and the humanly impossible promise. God has only said that the son
of promise would come from Abraham's body (Genesis 15:4), not from
Sarah's body. So what about using a concubine to get the promise to
come true?

Let's watch what happens when Abraham and Sarah try this.
Genesis 16:1-2: "Now Sarai, Abram's wife had borne him no children,
and she had an Egyptian maid whose name was Hagar. So Sarai said to
Abram, 'Now behold, the LORD has prevented me from bearing
children. Please go in to my maid; perhaps I will obtain children
through her.' And Abram listened to the voice of Sarai.'" Verse 15:
"So Hagar bore Abram a son; and Abram called the name of his son,
whom Hagar bore, Ishmael. Abram was eighty-six years old when Hagar
bore Ishmael to him."

This was not God's plan for how his promise would be fulfilled.
God's promise was going to depend on sovereign grace, not on human
ingenuity. Ishmael was not the son of promise, precisely because he
was humanly possible.

Look at Genesis 17:15-16 to see what God says about this. The
time is about thirteen years later. God comes to Abraham and says,
"As for Sarai your wife, you shall not call her name Sarai, but
Sarah shall be her name. I will bless her, and indeed I will give
you a son by her." This was a great setback to Abraham. He thought
he had a human way figured out to have heirs from his own body just
as God said he would.

Now God says, No, I will do it the impossible way, Abraham. So
Abraham's faith wavered for a moment and Genesis 17:17 says, "[He]
fell on his face and laughed, and said in his heart, 'Will a child
be born to a man one hundred years old? And will Sarah, who is
ninety years old, bear a child?'" And he pleaded with God to
fulfill his promise in a less spectacular way. Verse 18: "Abraham
said to God, 'Oh that Ishmael might live before You!' But God said,
'No, but Sarah your wife will bear you a son, and you shall call
his name Isaac; and I will establish My covenant with him for an
everlasting covenant for his descendants after him.'"

Why Won't He Settle for the Humanly Possible?

Why? Why won't God opt for anything less than the path of
impossibility? I think he tells us in the next chapter (Genesis
18:10-14). God comes to Abraham and makes the promise again:

"I will surely return to you at this time next year; and behold,
Sarah your wife will have a son." And Sarah was listening at the
tent door, which was behind him. Now Abraham and Sarah were old,
advanced in age; Sarah was past childbearing [not only barren all
her life, but now passed childbearing years]. Sarah laughed to
herself, saying, "After I have become old, shall I have pleasure,
my lord being old also?" And the LORD said to Abraham, "Why did
Sarah laugh, saying, 'Shall I indeed bear a child, when I am so
old?' Is anything too difficult for the LORD?"

There it is. That's the reason God will not settle for anything
less than the path of impossibility: He aims to show that nothing
is too difficult for the Lord. His purpose in all he does is

To magnify his sovereign grace And keep us in our humble
place.

This is "The Isaac Factor" - and it is exactly what God did.
Genesis 21:1-3: "Then the LORD took note of Sarah as He had said,
and the LORD did for Sarah as He had promised. So Sarah conceived
and bore a son to Abraham in his old age, at the appointed time of
which God had spoken to him. Abraham called the name of his son who
was born to him, whom Sarah bore to him, Isaac."

God planned and worked in a way that made the promise to Abraham
humanly impossible. 1) He saw to it that Sarah was barren from the
beginning. 2) He refused
the human solution of a legal heir named
Eliezer. 3) He rejected the human solution of having sex with Hagar
to beget Ishmael. 4) He waited till Abraham and Sarah were old and
she was beyond childbearing years before the child of promise was
born. 5) And he predicted the very time of the child's birth.

Implications for Us

In all these ways God acted to make clear that sovereign grace,
not human initiative, brings about children of promise. Now let me
apply this to us in two ways.

1. The first is that each of us who is a child of God - a member
of his saved covenant people, an heir of God's promise - became
what we are by sovereign grace, not human initiative.

You can see this application in Romans 9:6-9. Paul is wrestling
with the heartache that many of his fellow Jews are not believing
in Jesus Christ, the Messiah, and are therefore perishing (Romans
9:3). Does this mean that God's promise to his Jewish people has
failed? He answers in verse 6, "It is not as though the word of God
has failed." How does he explain this? He says in verse 6b, "For
they are not all Israel who are descended from Israel; (7a) nor are
they all children because they are Abraham's descendants." In other
words, to be an heir of the promises made to Abraham you can't just
be the product of ordinary human reproduction.

Then he goes right to our story of Isaac and the way Isaac came
into being to show what he means. He says in verse 7b, "But:
'THROUGH ISAAC YOUR DESCENDANTS WILL BE NAMED.'" In other words,
"Not Ishmael, the fruit of your human self-reliance, but through
Isaac the child whom I brought into being when it was humanly
impossible." Then Paul states the general principle that he is
drawing out of the story. Verse 8: "That is, it is not the children
of the flesh who are children of God, but the children of the
promise are regarded as descendants."

What is the difference between a "child of the flesh" and the
"children of promise"? The difference is that ordinary human
resources bring children of the flesh into being, but the sovereign
power of God's promise brings the children of promise into being.
You see this in verse 9: "For this is the word of promise: 'AT THIS
TIME I WILL COME, AND SARAH SHALL HAVE A SON.'" In other words,
Abraham tried to make an heir for God's promise by the human
initiative, that is, out of flesh (Ishmael), but God said, "No,
heirs of promise come into being through supernatural, divine
intervention. That is what it means to be a Christian - an heir of
God's covenant promises. That is how you became a Christian.

Know this. Cherish this. Be thankful for this with all your
heart. Be humbled by this. This is "The Isaac Factor."

God magnifies his sovereign grace And keeps us in our humble
place.

2. Finally, the second application is to the funding of
Education for Exultation. Is it possible that we could enter a $9
million educational and multi-purpose building in two years,
debt-free? The answer we offer is simply the word of God to Abraham
in Genesis 18:14, "Is anything too difficult for the LORD?"

Our hope and prayer is that God, in his great mercy, would look
upon our plan not as presumption but as one more expression of the
great Isaac Factor that runs through the whole Bible: God often
does things in a way that makes us depend on him for the humanly
impossible. Why?

To magnify his sovereign grace
And keep us in our humble place.