Genesis 21 — The Presence of the Past

This sermon is from Genesis chapter 21 and is entitled, The Presence of the Past.

Genesis 21 · chapter mention

It was delivered to Ekklesia Churches on Sunday, September 6, 2026.

We've spent a few months now with Abraham, and we've only got a few weeks left.

In the course of that time, we've watched him go through this process of being a man

of faith, but also a man who wrestles with God for control. Each of the major life events in the

life of Abraham have really helped to humanize him for me. I think going through his story in detail

has given me some insight into the human experience of what faith looks like in practice,

but I think it's also highlighted the faithfulness of God even in the midst of our imperfect faith.

I think we sometimes reduce the lives of these people in Scripture to a kind of montage of

their best moments.

We remember Abraham stepping out in faith to follow God's call to Canaan, and then Isaac

being born in his old age, and then the near sacrifice of Isaac in the next chapter.

But we forget all of the times that Abraham fell back on his own plans or went ahead with

horrendous plans of his own.

The time that he had a child with another woman in an effort to provide himself with an heir

instead of waiting on the one that God had promised.

Or the times that he hid behind his wife and tricked some of the most powerful men in the

region with the whole sister act thing.

And we forget all of the moments in between, the years that were filled with silent waiting

for God to fulfill his promise in his time.

And so the real picture of Abraham that starts to emerge is one that is not so different from people like you and I.

We're people who know that life isn't a highlight reel of moments,

but it's a daily experience of learning and growing and hopefully becoming more like Jesus as he works in us.

This passage opens up with the joyous occasion of Isaac's birth

and the confirmation that God does indeed keep his word.

Abraham and Sarah rejoice in this laughter that God has brought into their lives,

even after all of their mistakes.

But very quickly, the consequences of the past start to come back into the picture.

What will become of Abraham's son Ishmael?

And what part will Abraham play in his life?

What will happen as a result of the deception of Abimelech,

who comes back with the commander of his army for a conversation with Abraham.

And the question that I start to wrestle with is this,

what do I do with the existence of my past mistakes?

Specifically as a Christian, there is forgiveness in the name of Jesus,

but our choices have very real consequences.

And so the deeper question becomes, is God able to use even my broken past for his glory

and for my good?

And the answer is a resounding yes.

God is able to work all things together, even our past mistakes, for the good of those who

love him and trust him.

He truly is the everlasting God and the only one able to give us peace in the present and

hope for the future.

So let's begin by reading verses 1 through 7 and witness the joy of Abraham and Sarah

as they recognize how God has provided for them.

The Lord visited Sarah as he had said, and the Lord did to Sarah as he had promised.

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

Abraham called the name of his son who was born to him, whom Sarah bore him, Isaac.

And Abraham circumcised his son Isaac when he was eight days old as God had commanded him.

Abraham was a hundred years old when his son Isaac was born to him.

And Sarah said, God has made laughter for me.

Everyone who hears will laugh over me.

And she said, Who would have said to Abraham that Sarah would nurse children?

Yet I have born him a son in his old age.

And the child grew and was weaned.

And Abraham made a great feast on the day that Isaac was weaned.

These eight verses read like a victory shout, a confirmation that God does indeed keep his

promises.

Look at the repetition in the first two verses.

As he said, as he promised, of which God had spoken to him.

Repetition is an important tool in ancient literature.

It's like an exclamation mark that God keeps his word completely to Abraham and Sarah.

And the result of his kept word is a new kind of peace in the present that results in laughter.

Isaac's name means laughter.

And Sarah's whole perspective seems to have changed from mourning to laughter.

Like Psalm 30 verse 11 says,

Psalms 30:11

You have turned for me my mourning into dancing.

You have loosed my sackcloth and clothed me with gladness.

This celebration at age three is a big deal, and it's about more than just Isaac moving

on to solid foods, okay?

It's a celebration of him surviving longer than many infants did in that time.

So this huge feast is a culturally important one where they officially recognize Isaac

as the heir to Abraham, and it is a recognition of the way God has kept his promises.

When we are living in the confidence of a God who keeps his word, things start to change.

When our identity is wrapped up in the God we know and serve, we start to live in a way that is distinctly different.

Because we can't help it.

We stop taking ourselves so seriously and we live in the joy of the Lord.

I want to take a moment to address those who are teenagers or close to young adulthood.

I remember when I was probably 14 and I started to attend some youth events at a church and I really struggled at first.

I wanted so badly to be likable and when it came time to do various activities like play dodgeball, I just kind of stood in the background.

I was trying to protect my image as someone who didn't want to look like they cared too much, but inside I was terrified of not living up to expectations.

And I'll be forever grateful to an older kid named Chad who grabbed me by the shoulders

and said, hey man, stop trying to be so cool.

Have a little fun.

Chad was one of the few guys that were a few years older than me, and he opened up my eyes

to what life could be like when we stopped being the center of our own world.

It did take me a while, but in time, I became more confident in my identity in Christ.

And church gatherings and youth gatherings stopped being about me trying to prove myself

and started becoming about how to serve others and welcome them in.

My identity at school started to change into someone who was known less for coolness and

more for kindness.

Someone who could laugh at myself and sing loud and consider others because I was confident

in who God had called me to be.

I was confident not in myself, but in the God who promised to use me for his glory.

Even though Sarah is a 90-year-old woman living in the ancient Near East, I think Christians

of all ages can learn something from her transformation here, from a woman who began

by laughing cynically to herself in the tent and has now become a woman who can laugh freely

among others who are doing the same.

Once she was filled with cynicism, now she laughs at herself.

Once she hid alone in her tent, she now laughs with others.

And the absurdity of this moment, maybe even daring to laugh at her previous unbelief.

Proverbs 31 verse 25 describes a woman with character like this saying,

Proverbs 31:25

clothed in strength and dignity, she laughs at the time to come.

Christians are the only people in the world who are able to truly have peace in the present,

not because we are ignoring the brokenness that exists in the world around us,

not because we hold broken people at a distance and don't experience pain at times,

but because we know who gets the final word and who holds the final victory.

We know that our God faithfully keeps his promises,

And Jesus rising from the dead and defeating death itself is the proof of that.

For Sarah, her peace in the present was secured by this son given to her in her old age.

But our peace is secured by one who is even greater.

And his name is Jesus.

This is what Isaiah 9, 6 says about him.

It says,

For to us a child is born, to us a son is given,

And the government shall be upon his shoulders, and his name shall be called Wonderful Counselor,

Mighty God, Everlasting Father, Prince of Peace.

We could stop there, because all of that is true.

But verse 9 introduces a problem right in the middle of this celebration.

And that problem has to do with the mistakes of the past, and what consequences they might

hold for the future.

And the question Sarah and Abraham have to wrestle with is, does our God have the ability

to redeem the past?

Even in the moments that the past starts to bleed into the present.

Let's keep reading from verse 9.

For Sarah saw the son of Hagar the Egyptian, whom she had borne to Abraham, laughing.

So she said to Abraham, cast out this slave woman with her son.

For the son of this slave woman shall not be heir with my son Isaac.

And the thing was very displeasing to Abraham on account of his son.

But God said to Abraham,

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.

So Abraham rose early in the morning and took bread and a skin of water and gave it to Hagar,

putting it on her shoulder along with the child and sent her away.

And she departed and wandered in the wilderness of Beersheba.

The existence of Ishmael did present a real problem or threat to Isaac and the future of

the people who would come through him.

Just put yourself in Ishmael's sandals for a second here, though.

He's lived for 16 years as the only son of his father,

loved by Abraham, hated by Sarah because of what he represents to her.

None of this life is something that he has chosen,

but it is something that he's been born into.

And now another son has been born to Abraham,

and there's a feast in the honor of this three-year-old boy

who now is recognized as the only heir of your father.

And his laughter here reflects that.

So the word that's used for laughter here

is actually the inverse of Isaac's name

because it means a malicious or mocking laughter.

There is and will always be bad blood

between Ishmael and Isaac,

but Abraham's affection for Ishmael

is actually blinding him to this problem.

But not Sarah.

She sees the threat to her son.

And we see this tension develop between Sarah and Abraham over how to deal with this, right?

Sarah responds with a plan of her own.

A very similar plan to 16 years ago when Hagar was driven into the desert while carrying

Ishmael within her.

This time, Sarah is explicit, telling Abraham to cast her out.

And notice that she refers to Isaac as my son.

Sarah introduces a plan that comes out of a desire to protect her child, but also it comes

out of fear of what the past might mean for her future.

Abraham is caught between a rock and a hard place here because he loves Ishmael and wants

to be the one to bless him.

Any father wants to bless his son, but God intervenes here and kind of gives Abraham

some good news and some bad news.

The bad news is that Abraham will not be the one to bless Ishmael.

and it is God's plan to have him sent away from Abraham.

The good news though is that God will provide for Ishmael

and bless him because he is Abraham's son.

In verses 15 through 21 that come after this,

we find out that God again keeps his word

and does provide for Hagar and Ishmael.

He meets Hagar in the desert.

He gives her water and hope

and eventually Ishmael is married to an Egyptian woman

and becomes the father to the Ishmaelites, which is indeed a great nation as God promised.

God showed what we would call common grace to Ishmael, but his plan for saving grace

would come through the line of Isaac. Here's where it helps to have some New Testament

lens or perspective on this event. The Apostle Paul actually brings up Ishmael and Isaac

in Galatians chapter 4, verses 22 through 31. And he says that Ishmael and Isaac were a picture of

Galatians 4:22–31

two different approaches to salvation. Ishmael represented Abraham's attempt to provide for his

own salvation through effort. Paul says this is the kind of approach that like the Pharisees of

his day and others were trying to do, using the law to manufacture their own righteousness. But

represented the kind of salvation that could only be given by God, the only true salvation

that comes through his miraculous plan. Even the descendants of Ishmael would one day

find their only hope in the offspring of Isaac. Paul says that Christians receive the kind of

salvation that is a gift provided by God. And again, it's the only true salvation. Jesus is a

promise fulfilled through grace, not through our work and our plans, which in the end do not lead

to salvation. So what does this teach us about dealing with our past? Well, first you see two

opposite responses in Abraham and Sarah as they are trying to deal with their past mistakes.

Sarah is full of fear over it, and Abraham refuses to let go of it. And what God instructs them to do

is neither one of those things. God does not call them to fear. And at the same time,

he instructs Abraham to let go. So let's talk about Sarah's fear for a moment here. Fear that

even stole her peace for a time. Let me say this. God is not afraid of the mistakes that you have

made. He is able to work out all things, even broken things, for his glory. While our past sin

can have consequences for the present, sometimes painful ones, the sin of the past will never derail

the plan of God for your salvation. When you look back at your past, at mistakes made, you do not

have to live in fear that it's too much for God to handle, or that those mistakes can separate you

from the love and salvation of Jesus when you choose to repent and turn to him. Your sins are

washed away. As far as the east is from the west and you stand forgiven and new. And as for those

difficult consequences, things like leftover addictions and broken relationships and emotional

wounds, Jesus is willing to walk through those things with you while calling you to trust him

more and more, even when that means letting go of something. Sometimes we need to let go

of things that we can't do anything about and let God be the one to make it right in his timing.

I think, like Abraham, these are often relationships that we can't fix. Situations

where we have gone as far as we can to make things right and we have to let God handle the rest.

People who we desperately want to save, but we have to trust God to do that work in them.

Sometimes it means putting some distance between ourselves

and people who are more likely to influence us than be influenced by us.

Walking forward from the mistakes of the past requires that we continually trust God, though,

and that we trust him enough to walk forward in his wisdom.

And Abraham is going to need some serious wisdom for what's coming, as another ghost of the past

threatens his future. Let's read verses 22 through 34 together.

At that time, Abimelech and Phicol, the commander of his army, said to Abraham,

God is with you in all that you do. Now, therefore, swear to me here by God that you will not deal

falsely with me or with my descendants or with my posterity. But as I have dealt kindly with you,

so you will deal with me and with the land where you have sojourned. And Abraham said,

I will swear. When Abraham reproved Abimelech about a well of water that Abimelech's servants

had seized, Abimelech said, I do not know who has done this thing. You did not tell me,

and I have not heard of it until today. So Abraham took sheep and oxen and gave them to Abimelech,

and the two men made a covenant. Abraham set seven ewe lambs of the flock apart,

and Abimelech said to Abraham, What is the meaning of these seven ewe lambs that you have

set apart? Then he said, These seven ewe lambs you will take from my hand, that this may be a witness

for me that I dug this well. Therefore, that place was called Beersheba, because there both of them

swore an oath. So they made a covenant at Beersheba. Then Abimelech and Phicol, the commander of his

army, rose up and returned to the land of the Philistines. Abraham planted a tamarisk tree in

Beersheba and called there on the name of the Lord, the everlasting God. And Abraham sojourned

many days in the land of the Philistines. Abraham has history with Abimelech, and it's not good

history. In fact, when they parted ways last, Abimelech had only narrowly escaped a destruction

caused by Abraham's dishonesty. If you've ever run into someone that you've got unpleasant history

with, you can kind of understand what Abraham must have felt like. But further complicating

things is that Abimelech brings the commander of his armed forces with him. He's not here for tea.

He's come for some sort of military agreement. Fortunately, it sounds like Abimelech continues

to recognize that Abraham's God is not someone he wants to cross. So the purpose of this meeting

is to broker a kind of deal or treaty between the two people groups to prevent further conflict.

And in the conversation between the two men, Abraham shows a remarkable amount of maturity

compared with times past.

He doesn't cower, but he also doesn't wield his strength over Abimelech.

He's firm, but he's fair.

Because there were no written agreements at this time, this treaty would have been sealed

with some kind of symbolic exchange between the two leaders.

Very similar to the thousand pieces of silver that Abimelech had given Abraham in the last chapter.

But the symbolism of the seven female lambs is lost even on Abimelech because it has to do with spoken Hebrew.

So he asks for an explanation.

See, in Hebrew, the word seven sounds like the word oath.

So this gift of seven lambs is to memorialize the oath that is made here.

a kind of reminder for the generations to come as their flock grew to remember the deal with Abraham and his people.

As the leader of his people, Abraham's responsibility is to lead them both with humility and wisdom,

and he is finally beginning to trust God with both of those things.

The future of a people often rises and falls on the humility and the wisdom of their leadership.

And that's always going to involve some aspect of dealing with the past and its implications

for the future.

Abraham needs the wisdom of God to continue leading well.

And there's kind of three things that stand out for us here.

First, he is bold.

He doesn't shrink back from addressing the important issues because he knows that God

is his shield.

He can speak with truth and confidence and deal with these vital issues like water rights.

Second, though, he acts with humility.

He does not mistreat Abimelech because he perceives that he has the upper hand in this situation.

He knows that while pushing Abimelech away might be easier on his pride,

it is better for the future of his people to act justly here.

Both of these things show us Abraham is developing as a leader,

but the most important thing that he does happens after Abimelech leaves.

In verse 33, Abraham turns his eyes from the present to the future and he sets his sights

on the everlasting God.

Abraham calls on the name of the Lord, specifically seeing him as the everlasting God.

Abraham worships.

He recognizes that his future and the future of his people does not rest on even the best

alliance or treaty with man, but it rests on God's provision for them.

He's finally starting to get it.

God is able to use the entirety of our lives, the good, the bad, and the ugly, to form us

into people who begin to look more like Jesus.

And we call this process sanctification.

Just means being made holy, being made like Jesus.

But I want to make sure I'm being clear that this process follows the moment of our salvation.

We don't work our way up to being saved by Jesus.

We are saved in the moment that we respond to the call of Jesus,

the call to turn from our sin and follow him as our Lord and Savior.

Like the gavel hitting the desk of a judge, we are declared righteous in that moment

because we have received the righteousness of Jesus.

there's no process to earn that because we never could earn that Jesus did all the work

and invited us to all of the benefit and from that point on you are saved and you can be confident in

that and you can be confident that Jesus is going to continue this process of changing you from that

point on this process of being made more like Jesus happens over the course of a lifetime I think we

can all agree that this Abraham in Genesis 21 looks nothing like the man who left Ur of the

Chaldeans. He's been put through fire and heated and refined and corrected. If our salvation is like

the declaration of a judge's gavel, our sanctification is like the ongoing strikes

of a blacksmith's hammer, put through heat and refined and shaped and formed by the work of

Christ in us. So the invitation of Jesus is not to a perfect performance, but it's to the process

of being perfected. This is a process that he began when he invited you to follow him, and he will

complete in the end. Scripture says that Jesus is the author and the perfecter of our faith in

Hebrews. The prophet Micah poses the question then, what does it look like to participate in

that process? What does it look like to live a life that pleases God? In Micah 6, 8, he says this,

he has told you, oh man, what is good. And what does the Lord require of you, but to do justice,

to love kindness, and to walk humbly with your God. So I would invite you to do the same,

to come to Jesus, to walk with him in humility all the days of your life,

to believe that you are a new creation in Christ,

and that he is not only able to deal with the mistakes of your past,

he is able to forgive those things, but also to walk with you in the present

and to lead you into a future that is filled with hope.

Ekklesia is a church of house churches gathering weekly in Council Bluffs, Iowa, and in homes throughout the week.

We are a Bible-centered church focused on preaching from Scripture and making disciples of Jesus.

You can learn more about what we believe and contact a pastor at ekklesiachurches.org.