Our God is a Promise Keeper - Genesis 21:1-34

Genesis 21
Our God is a Promise Keeper
INTRO
Before we move into Genesis chapter 21 this morning. Please turn with me to
(Matthew 5:33-37). JESUS has clear instructions on making promises.
“Again you have heard that it was said to those of old, ‘You shall not swear
falsely, but shall perform to the Lord what you have sworn.’ But I say to you, Do
not take an oath at all, either by heaven, for it is the throne of God, or by the
earth, for it is his footstool, or by Jerusalem, for it is the city of the great King.
And do not take an oath by your head, for you cannot make one hair white or
black. Let what you say be simply ‘Yes’ or ‘No’; anything more than this comes
from evil.”
An oath or solemn promise. JESUS takes serious the promises we make.
Saying to not swear by anything to verify that it will be done but simply “Let
what you say be simply ‘Yes’ or ‘No’; anything more than this comes from evil.”
In light of our Lord’s instruction here I rarely if at all use the word promise or
make a vow. Not that it’s wrong to do so,…. but that there is great weight
behind doing so. Often times along with my ‘Yes’ if that is what I say, I will
include “Yes..I aim to do so” or “I have full intentions,..Lord willing” because in
all honesty something may come up that prevents it from being fulfilled OR I
simply fail to follow through as I said I would. This could be something in the
realm of “Dad, would you play catch with me today?”….. “I’d love to son…and
there should be no reason why we won’t be able to…so let’s plan on it.” And
what is intended to take place…takes place….most of the time. But there are
times where I don’t follow through for a number of reasons….some…..justifiable
ones,….but also by cause of simply failing on my part to do so. And that hurts.
Whether it be not playing catch with my son or of commitments of much
greater magnitude.
We all know that place of being promise breakers….ourselves…and also being
the recipient of promises made to us,…..being broken. In our fallen sinful
state, this takes place.
There is one….and one only, however who never breaks His promises. And
that is our “Everlasting Father”. Our God is a Promise Keeper. He makes
promises and He fulfills every last one of them. Our God is a Promise Keeper.
And that is pinnacle TRUTH I want us to receive deep into our hearts this

morning. Receive and remain abiding. Our God is a Promise Keeper. Now
with this abiding in your heart, I aim to expound upon it in 3 fold measure in
today’s sermon. First and foremost, like every promise God makes… seeing
God’s Promise to Abraham come to pass in the birth of Isaac. God’s promise…
fulfilled Our First point
BODY
1)
FIRST POINT - (Genesis 21:1-7).
Promise . Fulfilled
Promise . Fulfilled,…Read with me the first 2 verses of the 7 we’ll be looking at
with this point and note the intentionality in God’s Word to emphasize God’s
Promise Fulfilled. Hear the intentionality there Saints and receive it as comfort
to your soul where any trouble lies upon your heart in growing weary or in
bearing frightful doubt of waiting upon God to come through on His promises.
- read
“….as he had said,…as he had promised,…at the time God had spoken to him”
God will fulfill every promise of His at the proper time.
WHAT Promise or Promises of God’s right now,..in this season of life of yours,
…are you waiting on Him for? Perhaps it involves the promises in God’s Word
as it relates to raising children. Maybe it’s promises of God in assuring us of His
provision in our lives. Food, shelter and clothing. Maybe it’s in regards to
relationships, relationships with nonbelievers, with believers, with those closest
to us. “….as he had said,…as he had promised,…at the time God had spoken
to him”. God’s Promise made to Abraham was fulfilled. By FAITH, We believe in
the same God as Abraham, by FAITH we worship the same God as Abraham, by
FAITH we can trust the same God as Abraham,…that He will fulfill every
promise of His made to us.
Our response to God on this truth is represented well here in the next 5 verses.
The response is one of obedience and testimony. Let’s read these 5 verses
and identify them along the way. - read
Starting with (3 and 4) When did this command come? Back in (Genesis
17:19). One of the times God was reassuring to Abraham of His covenant with
him…and Abraham…very old and…99 years old to be precise…and still
childless,…is pleading with God that the promise would come through his son
Ishmael,…born to him by Hagar who is 13yrs old at the time. “God said, “No,
but Sarah your wife shall bear you a son, and you shall call his name Isaac. I will

establish my covenant with him as an everlasting covenant for his oﬀspring after
him.” Abraham obeys God on this command now seeing,…with his own very
eyes,…the fulfillment of it. He names his son Isaac which means “One who
laughs or one who rejoices”. He continues his obedience to God by
circumcising his son Isaac on the eighth day of life as instructed by God in
(verses 10-14) of that same chapter 17 of Genesis.
ALL TO SAY…Obedience and Gods promises Go hand and hand.
For strong emphases on this I oﬀer to you to read (Deuteronomy chapter 28)
These passages provide clear layout of the great blessing for obedience and
troubling curses for disobedience. WE may not be facing nations in war NOR
have crops to harvest that we depend upon alone as our source of food…. but
the principles obtained in the treasury of God’s Word in those passages…..
(Deuteronomy chapter 28) ……the principles are wise to take seriously.
Obedience and God’s promises Go hand and hand. YOU may be asking,…
“Well what do I obey? I am not knowledgable in God’s Word. I know-verylittle.” To this I would say…Obey what you know. Obey what you know. Obey
God in what you Know…and Regularly seek to Know God more and as He
reveals more of Himself to you in His Word,….continue to respond to His grace
in doing so by obedience to what He reveals. God’s Word sanctifies. (John
17:17) “Your Word is Truth. Sanctify them in the Truth.” …. God’s Word
sanctifies. …..Which means…to put it in very simple terms. It exposes sin in
your life …by the working of the Spirit of God…the Word of God exposes sin to
confess, repent and turn away from and it leads you to greater manifestations
of Christlikeness in your life. God’s Word sanctifies. Obedience and God’s
Promises Go hand and hand.
As do the wonderful testimonies we have the joy to share about to the glory of
God of His promises believed by faith coming to pass in our lives.
Give testimony.
LOOK at (verses 5 - 7). - read
It’s like, ….Sarah would be saying to all she knows… “Do you want to hear
something amazing?!. I was barren…like forever, have always been
barren….and menopause…(pﬀﬀ..) that ship sailed by long ago….. And check it
out. I am now nursing my son whom I gave birth to by my 100 year old husband
over there…just as God promised I would.” “What!! You’re kidding right?” “No,
not in the least. We have even given him the name Isaac, as God told us to,
which means, get this… ‘One who laughs or One who rejoices.’ Fitting right?.”
“That’s amazing! WOW! Ha ha…I am seeing the impossible with my own
very eyes.”
And that is it…isn’t it? Seeing the impossible with our own very

eyes. God’s promises fulfilled, the impossible being witnessed by your very own
eyes,…are to be testified to that we may bring glory to His name.
Another question to lay before you then. What promises of God have
come to pass that you may give testimony to and thereby bring glory to His
name?
Think on what they are. Know them and testify of them.
A warm up for you. If you love Jesus. Give testimony of God’s saving
faithfulness in your life. That promise found in (Psalm 69:13) “Christians
prayed for me, Christians shared Jesus with me. GOD, who is rich in mercy,
answered their prayers and worked powerfully in me to believe in the gospel
message of Jesus Christ. For those who shared the gospel message with me
embodied Paul’s words in” (1 Corinthians 15:14) “For I delivered to you as of
first importance what I also received: that Christ died for our sins in accordance
with the Scriptures, that he was buried, that he was raised on the third day in
accordance with the Scriptures,” The message of the cross of Jesus Christ. (1
Corinthians 1:18) “For the word of the cross is folly to those who are perishing,
but to us who are being saved it is….the power of God.” “I know this power…I
know this power…God SAVED me. Hallelujah…Praise the Lord… God SAVED
me! …..I BELIEVE! I testify to His promise to powerfully save sinners such as I
who now loves and longs to be with Jesus continually who is my Lord and
Savior.”
Our God is a promise keeper who Fulfills every Promise made. Promises we
are to walk in Christian….amen? And this is where God’s Word is going to
apply an uncomfortable amount of pressure….for all of us. For walking in
God’s promises means we are walking in freedom. And this is easy to say….but
not easy to fully do. This second point I am stating as Promise verses Law.
Seen in (verses 8-21)
2)
SECOND POINT - (Genesis 21:8-21).
Promise verses Law
Promise verses Law. There is a story piece here that has some heartache in it
yet another beautiful testimony of our God being a promise keeper. Hagar and
Ishmael. To refresh ourselves with who they are and why they are here I’ll
remind you of what we learned about them in chapter 16 of Genesis.
5 chapters ago. They were brought into the storyline of God’s redemptive work
by the ones He made a covenant with to do so. Abram and Sarai. Sarai
devises a plan that Abram doesn’t flinch to get on board with. The plan in
essence. We are going to help God out. His promise is taking a while….let’s
take matters into our own hands….and get’r done. Sarai acquired a slave

woman when they were in Egypt during the famine…her name is Hagar,…and
she (Sarai) took Hagar and gave her to Abram to have as a wife that Sarai may
have children through her. This work of the flesh…not of the promise…but work
of the flesh…works…in that she (Hagar) conceived and bore a son to Abram
who named the child Ishmael. But this wasn’t according to the promise God
made to Abram and God would not accept Ishmael…a work of the flesh…to be
the one through whom God would fulfill His promise. God does show
compassion to Hagar and the child as we will see fulfilled here in the text but
God does not accept this work of the flesh which is now present, Hagar and
Ishmael present….in the picture and a regular contention piece within
Abraham’s household. SO that is who they are and why they are here in the
midst of all that is going on.
Back to the storyline piece now. Isaac is born, has grown to the age of being
weaned…Ancient Hebrews completed weaning at about three years of age.
Abraham is throwing a party to celebrate it. So we could conservatively could
say..Isaac, at this point, was at least 2yrs old and likely more?… Which means
Ishmael then is probably about 16 years of age at this point. We know he was
13yrs old when he was circumcised..chapter 17 tells us that…it’s been over 2,
if not 3 years now…He is a budding adolescent teenage boy. And we all no
how bridled in tongue and respectful they can be. Right on cue with that,
Ishmael laughs, which we can understand to be an act of mockery…not the
laughter of “One who Rejoices” like the name Isaac means….but a laugh or
forms of expression that exhibit clear mockery at the target. Isaac…a baby…is
the target and Ishmael, 16y/o teenager, is the one delivering the blows.
Momma bear Sarah who witnessed the whole thing doesn’t miss a beat. She
goes straight to Abraham in (Verse 10) saying. “Cast out this slave woman with
her son, for the son of this slave woman shall not be heir with my son Isaac.”
This is very upsetting to Abraham, and understandable so…but watch this
(verse 12&13). God says to Abraham. “Be not displeased because of the boy
(that’d be Ishmael) 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.” God doesn’t rebuke Sarah for such a harsh demand to her husband,
…but rather aﬃrms it. WHY?
Hold that question. We’ll get there
shortly. First let’s finish the storyline. God aﬃrms Sarah’s demand to Abraham
to cast out this slave woman with her son. As if saying,… “these two…..Son of
promise and son by man’s eﬀorts…by works of the flesh,….cannot go together.
God aﬃrms…cast them out,…cast the work of the flesh out…but know this…

which is so awesome of our God. Know this…“I (God says) I will make a nation
of the son of the slave woman also, because he is your oﬀspring.” Which is not
a new statement but rather honoring His promise made to Hagar back in
chapter 16 of Genesis when God hears the cries of the rejected, alone and
pregnant Hagar and visits her with this wonderful promise in (verse 10&11) of
that chapter.
“I will surely multiply your oﬀspring so that they cannot be numbered for
multitude.” ….“Behold, you are pregnant and shall bear a son. You shall call his
name Ishmael, because the LORD has listened to your aﬄiction.”
The Lord listened to Hagar’s aﬄiction, makes this promise to her and shows to
Abraham … in this moment here (verses 13&14 of chapter 21) shows … His
undying faithfulness in keeping it. Our God is a promise keeper. God makes
this promise to Hagar who is cast out of her home for good…not to return…sent
into the wilderness with only some bread and a skin of water for her and her 16
y/o son Ishmael. The two of them very much fitting the picture of a widow
and a fatherless child.…and even that of sojourners…wondering the wilderness
with no place to call home. Abraham is alive YES, but this action of casting her
out of his care and oversight renders her in the same despairing predicament of
a widow…and their son…as being fatherless…and both as sojourners without a
home.
Alone in the wilderness…weak…destitute and now aﬄicted with thirst….
more or less are in a place of…awaiting death. This is captured for us in
(verses 15&16). It is here where. “The LORD who watches over the sojourners;
who upholds the widow and the fatherless, thats…(Psalm 146:9)…” It is here,
in (verses 17 & 18) of our text,….where this Lord of ours,…hears their cries
and provides for them. Our God is a promise keeper and He fulfills His promise
HE made to her. He hears their cries and provides for them. In (Verses 19-21)
we see GOD provide water, provide an ability for Ishmael to make a living as
becoming an expert with the bow and then ultimately a wife from his mom’s
homeland of EGYPT,…whereby God’s promise to multiply Hagar’s oﬀspring is
fulfilled…which He does…through the line of Ishmael a great nation comes.
Heartache in the storyline piece yet another beautiful testimony of our God
being a promise keeper.
And WHY was God okay with Hagar and Ishmael being cast out? WHY did He
aﬃrm Sarah’s demands to her husband Abraham to do so? I believe it has to do
with what this storyline teaches us as an allegory. Teaching us that to walk in
the freedom of God’s promises,…TO WALK IN THEM….we must cast out
enslavement to the law…to the works of the flesh. We must cast that all out of

our lives. Remember this second point is stated as Promise verse Law. Or
you could think of it this way…. Freedom verses Slavery.
As I stated at the onset of this point….THIS is where God’s Word is going to
apply an uncomfortable amount of pressure….for all of us. For walking in
God’s promises means we are walking in freedom. And this is easy to
say….but not easy to fully do.
“Preacher, you said this is an allegory. Where do you getting that?” Well, I’ll
show you. Turn with me to Galatians chapter 4.
Paul is contending strong in this epistle against a works based righteousness.
Saying that if we are in Christ, if we believe all the promises of God find their
yes in Christ (2 Corinthians 1:20), that if we believe in a righteousness of God
that depends on faith (Philippians 3:9, Romans 4:16)…then we are sons and
fellow heirs to the promise to the promise (Galatians 4:23)…according to the
oﬀspring of Abraham. If this is you,….who you are,…then the allegory of the
free woman represented by Sarah and the slave woman represented by Hagar,
….has a lesson to teach us.
And this is what I intend in (verses 21-31) of his argument in Galatians 4 to
draw our attention to…for what it teaches us in regards to walking in the
freedom God has promised and purchased for us in Christ. - read
And though it would take an entire sermon if not more to fully unpack what is in
there,…..the key truth I want to draw our attention to in it,….for application of
walking in the freedom God has for us in regards to casting out all that would
bring mockery…all that would go against…all forms of persecution to the
promise of righteousness that depends on faith in which we have in Christ and
are to walk in the freedom of. This would be Anything,….anything that one
would do or impose upon others in thinking it adds to God’s saving work in
their life and ones righteous standing before God. Any work of the
flesh….helping God out,….so to speak. ANYTHING. The Righteousness of
God is a “Righteousness that depends upon faith….” it is an imputed
righteousness on the merits of Christ’s Righteousness…His spotless, sinless,
perfectly obedient, submitting to the Father’s will in totality…LIFE. Any work of
the flesh that would bring mockery to that MUST be cast out of our lives. If it
shows it’s face…cast it out!
And this includes,…now listen…here’s the pressure. This includes - not
being known. Withholding who we are. What we are struggling with. What
fears we have. What lies we are tempted to believe. What temptations we
suﬀer from. What sins we are guilty of.

Matt Chandler, a pastor and author stated it this way. “Being 99%
known is not being known at all”…. “Being 99% known is not being known at
all”. IF that is you…IF that is I…we are enslaved to that 1%. And IF a slave to
1% then a slave we are,….and are not fully walking in the freedom God
promises we are able to walk in through the gospel of His beloved son.
God promises righteousness by faith….we have a sinful bent to challenge it with
works of righteousness. Either by adding to it OR by putting up a facade to
paint a picture of what is not real. Concealing that which is real…the very
things God is calling us to walk in the freedom in…concealing it keeps us
enslaved to IT. God is saying cast that out. It doesn’t belong.
(Galatians 5:1) “For freedom Christ has set us free; stand firm therefore, and do
not submit again to a yoke of slavery.” The yoke of trying to portray a facade of
who we are not,….is a heavy and exhausting yoke to bear. Cast is out God
says.
Consider this…If I put upon myself…OR,…if I put upon anyone else for that
matter…something more…something to add to the finished work Christ has
done to set me free,…to set us free. IF, figuratively speaking, I say…. “I’m going
to bear this additional burden…this additional yoke, OR, here…you bear this
additional yoke with me to add to the light one Christ told us we are to to bear
alone.”
How would you describe me as being to myself?…OR,.. if imposed
upon another, what would doing so describe me as being? Oppressive.
Oppressive. So also is the yoke of trying to portray a facade of who we are not.
I preach this not as one who is innocent in remaining enslaved. But we must
hear this Word from God and receive it into our hearts and in His strength act on
it if we are to experience the fullness of the freedom Christ died to purchase for
us. It cost him is life,…Saints. He bore the shame and guilt of it all to set us
free to say YES this is true of me, YES this was who I am and where I am
presently at and praise be to God the blood of Jesus cleanses me of all
unrighteousness.
I am a child of God by faith and He who began a good work in me is
faithful to bring it to completion. Do you hear that…he is not done with me. No
matter what the baggage I bring. HE is not done with me and I am free to be
known. It’s his burden to bear. He came to bear it for me, how dare I insult him
by reaching to put it back on. It is my redemption song I am to sing and give
praise to His name for,…ALL because of the gospel of Jesus Christ.
(Galatians 5:1) “For freedom Christ has set us free; stand firm therefore, and do
not submit again to a yoke of slavery.” Whenever a yoke of slavery shows up to
mock God’s work of grace in your life. Cast-it-out and live free.

How does this look in relationships? I believe our closing point provides a
helpful example of walking in this freedom of God’s promises.
3)
CONCLUSION. - (Genesis 21:22-34)
Promise in Relationships
Third and concluding point. Promise in Relationships
An example of walking in this freedom of God’s promises as shown to us by
Abraham’s dealings with Abimelech in the final verses of chapter 21
(verses 22-34)
Abimelech. Do you remember him? This is not the first interaction Abraham
and Abimelech have had. The prior chapter, chapter 20 is dedicated to their
meeting and first time interaction. And I’ll say this. Abimelech shines and
Abraham doesn’t in that chapter. Abraham clearly wrongs Abimelech…
repeating a sin he does in the past of being deceitful of who Sarah is…namely
presents her as his sister and not his wife. He plays the sister card again out of
fear for his own skin and Abimelech, believing Abraham and Sarah’s
story….sends for Sarah to take her to be one of his wives. And before he “had
approached her…” before he had any sexual relations with her…God visits him
in a dream by night and says. ….(Genesis 20:3). “Behold, you are a dead man
because of the woman whom you have taken, for she is a man’s wife.” How
terrifying would that be? And a type of judgment came to his home for God told
him…as a part of making things right….Abraham needed to pray for Abimelech
“so that he shall live.” (Genesis 20:7) And this included his whole household
for God had “closed all the wombs of the house of Abimelech because of
Sarah, Abraham’s wife.”
That’s heavy. Abimelech contended that he was innocent and he was! YET the
acts of Abraham adversely aﬀected Abimelech and his whole household. Not a
good start to their relationship. But God intervenes and peace is made between
them.
NOW, how do we see this peace between them lived out in walking
in this freedom of God’s promises?
Well, for starters…there is peace between them. The gospel message is a
message of peace. It promises peace. First and foremost. Peace between us
‘sinners’ and God who is ‘Holy’. The gospel is a message of peace. It’s part of
the spiritual armor we put on….(Ephesians 6:15). “..and, as shoes for your
feet, having put on the readiness given by the gospel of peace.”
“For in him (in Jesus) (Colossians 1:19-22). For in him all the fullness of God
was pleased to dwell, and through him to reconcile to himself all things,
whether on earth or in heaven, making peace by the blood of his cross. And

you (you and I), who once were alienated and hostile in mind, doing evil deeds,
he has now reconciled in his body of flesh by his death, in order to present you
holy and blameless and above reproach before him,…”. making peace by the
blood of his cross. And this translates first, vertically between us and God and
then horizontally…..between one another. The hostility against one another in
our world today is razor sharp and the only remedy is the gospel of Jesus
Christ…the gospel of peace. JESUS is the remedy. JESUS… “The prince of
Peace.” (Isaiah 9:6).
There was once not peace between Abraham and Abimelech…and now there is.
And the example of this carries into the first few verses (verses 22-24) where
Abimelech seeks to strengthen their now good and peaceful relationship as
neighbors by an oath…or promise. - read
A pleasant interaction. Abraham swears…Agrees to this promises between the
two of them,….to live at peace with each other. And inevitable….as in life…this
gets tested. (verse 25) is the start of a whole other scene. TIME has passed
between (verses 24 & 25). This is a whole other scene. A scene in which a
wrong has been committed and it’s being confronted between them. A ripe
example for us to learn from.
Let’s read through this dialogue between them on the matter and I ask you to
please pay attention to some marks of walking in this freedom of God’s
promises. Note the Respectful Openness that is present between them. Very
open yet not defensive or hostile to any degree. Note that Abraham
reproves…. which is a correction given gently with kind intent. He doesn’t raise
an accusation against Abimelech who respectfully conveys his innocence. And
then the Eagerness they share to make things right along with the great cost it
comes with to do so. Which implies taking the matter seriously and carefully in
working together for absolute resolve. They go to great lengths to ensure
everything is clear and well between them. (verses 25-30) - read
And what is the result?…They continue to live at peace with one another and
mark the place where this covenant is made by naming it Beersheba (verse 31)
Which, by the way…a side note…Beersheba can be visited today…It’s One of
the largest city’s in Israel second only to Jerusalem. It’s on today’s map…
Beersheba which means “Well of Seven or Well of the Oath”.
As named by Abraham and Abimelech,…marking this occasion where peace
between them was preserved and by oath,…whereby they continued to live at
peace with one another,….and so should our aim be who walk in the freedom of

God’s promises purchased for us by Christ….As Paul states it in….(Romans
12:18). “If possible, so far as it depends on you, live peaceably with all.”
And the gospel message of Jesus Christ is God’s promise provision to us as the
way to do so. And our God is a promise keeper. Always trustworthy and
always faithful to His Word.
So like Abraham, in (verses 33-34) “..who plants a tamarisk tree in Beersheba
and called there on the name of the LORD, the Everlasting God. And
….sojourned many days in the land of the Philistines.” So should we, as
sojourners ourselves in this world but not of it (John 15:18-19) So should we
plant firm in our hearts, like a tree deeply rooted by a well,…plant deep in our
heats to call upon the name of Lord and worship this great Everlasting God with
all our lives unashamedly…walking in the freedom of God’s promises purchased
for us by Christ all the days of our lives. For Our God is a promise Keeper.

- PRAY
COMMUNION
(Romans 8:1-4) says….. “There is therefore now no condemnation for those
who are in Christ Jesus. For the law of the Spirit of life has set you free in Christ
Jesus from the law of sin and death. For God has done what the law, weakened
by the flesh, could not do. By sending his own Son in the likeness of sinful flesh
and for sin, he condemned sin in the flesh, in order that the righteous
requirement of the law might be fulfilled in us, who walk not according to the
flesh but according to the Spirit.”
The table is open that commemorates the life and sacrifice JESUS gave that
we may be set free. As the music team leads us in a time of responding to
God’s Word….i invite you, the believer, I invite you forward to partake of the
elements of communion and declare his death till he returns.
BENEDICTION
(Joshua 21:45)


Related Media
Related Sermons