Home   e-Library       中文 
e-Library Home |  Browse By Category |  Study the Bible    
Abraham Has Two Sons

Abraham Has Two Sons

Based on a sermon by HH Ko—Heidelberg, Germany

            For it is written that Abraham had two sons: the one by a bondwoman, the other by a freewoman. (Gal 4:22)

Typically, the fact that an individual has two sons is unremarkable. However, in the case of Abraham, his two sons Ishmael and Isaac are very remarkable. The actions and consequences of this particular family transcend time and are significant to us even now. They illustrate an important understanding concerning the family of God and the issue of salvation, which is the inheritance given to children of the promise.

Ishmael and Isaac were borne to Abraham under special circumstances. God promised Abraham (then called Abram) that his descendents would be as numerous as the dust of the earth and the stars in the sky.

In Genesis 15:4, God reiterated to Abram the promise that He would give him an heir from his own body. Abram was almost eighty years old at this time. For as long as he was married to Sarah (then called Sarai), she was barren. How could God give him children?

After Abram had lived in Canaan for ten years, he was still childless, so Sarai gave him her maidservant Hagar, so that through her, he could have offspring.1 Indeed, Hagar conceived and gave birth to Ishmael.

Thirteen years later, God appeared to Abraham, and told him that Sarah would bear him a son. When Abraham was one hundred years old, Sarah gave birth to Isaac. When Isaac was born, Ishmael was fourteen years old.


Immediately, we notice differences in the births of Ishmael and Isaac. Isaac was anticipated with patience for twenty-five years; Ishmael was conceived as an impatient impulse. God named both children before they were born, but Isaac was named before he was even conceived,2 while Ishmael was named in his mother’s womb.3

While Hagar was pregnant with Ishmael, the family was in turmoil and she ran away from her abusive mistress. On the contrary, the birth of Isaac was surrounded with laughter: Sarah laughed when angels told her about it,4 and all who heard of this matter laughed as well.5

Ishmael was born to Abram; Isaac was born to Abraham. Isaac was circumcised when he was eight days old, while Ishmael was circumcised when he was thirteen years old. As for their mothers, Ishmael was born of a fertile bondwoman, while Isaac was born of a barren freewoman. Ishmael was born of human willfulness, Isaac was born of God’s promise.

In both cases, God showed mercy and love towards the sons because they were of Abraham.

Two Sons, but Only One Heir

After his sons were born, Abraham’s family grew up. When Isaac was weaned, Abraham held a great feast. At this time, Sarah saw that Ishmael scoffed at Isaac and demanded that Abraham cast out Hagar and Ishmael:

            “Cast out this bondwoman and her son; for the son of this bondwoman shall not be heir with my son, namely with Isaac.” (Gen 21:10)

Initially, it appears that in a moment of maternal anger, Sarah demanded that Ishmael be cast out because he mocked little Isaac. If we read more carefully, Sarah’s main concern was the matter of inheritance, and not that her son was being bullied. She wanted Isaac to be the sole heir.

As cruel as Sarah’s demand was, God agreed with her, saying “‘Whatever Sarah has said to you, listen to her voice; for in Isaac your seed shall be called’” (Gen 21:12).

Sarah’s demand displeased Abraham, because Ishmael was his son. For more than thirteen years, whenever Ishmael called out for his father, Abraham was there, responding to his son’s needs. Now, Sarah wanted Ishmael to be sent away, and God agreed with this course of action.

Abraham was in quite a predicament: he loved his son, and yet, God confirmed that it would be through Isaac that His promise would be fulfilled.

Was there an alternative course of action that Abraham could have taken? He was a rich man. It was within his power to build a separate maid quarter for Hagar and Ishmael, and not have to cast them away. Why was this not a viable option?

In this incident, we see both the justice and mercy of God. Isaac was the son of promise, born of Abraham’s wife Sarah, and in keeping with the promise, Isaac was to be the sole heir. In this sense, Ishmael, born outside of God’s promise, had to be sent away. Yet, out of mercy to Ishmael, God reassured Abraham that he would be taken care of:

            “Do not let it be displeasing in your sight because of the lad or because of your bondwoman. Whatever Sarah has said to you, listen to her voice; for in Isaac your seed shall be called. Yet I will also make a nation of the son of the bondwoman, because he is your seed.” (Gen 21:12, 13)

With this assurance, Abraham obediently did as God asked. He gave Hagar and Ishmael bread and water and sent them away. Abraham did not cast them away as Sarah had demanded, but sent them away.6

These two methods of departure are drastically different. To be sent away is to depart with goodwill and with a purpose, in the same way God sent prophets to the people bearing a message. To be cast away is as if you are chasing out a stray animal from your home.

Abraham personally prepared bread and water, set the provisions on Hagar’s shoulders, and sent her away with Ishmael. In these gestures, we can see how Abraham cared for Hagar and Ishmael. Although he cared greatly for his son, and his son’s mother, he abided by God’s command to send them away from Isaac, the son of the promise.

Indeed, God did take care of and provide for Ishmael and Hagar.7 We can see that although Ishmael was born outside of God’s promise, God accepted the fact that he existed, and showed mercy towards him. Despite this, Ishmael had no part in his father’s inheritance.


In Galatians, Paul writes that Abraham had two sons; yet in God’s eyes, Abraham had only one son:

             “Take now your son, your only son Isaac, whom you love…” (Gen 22:2)

However, in total, Abraham had more than two sons: he had six other sons with Keturah, the wife he took after Sarah died.8 Even though he had these other sons, he sent them away from Isaac, and the Bible records that these six sons were Keturah’s sons, and not Abraham’s: “All these were the children of Keturah” (Gen 25:4b).

In the same passage, the Bible records unequivocally that while Abraham gave gifts to his other sons, he gave all that he had to Isaac. Even though Abraham showed concern and generosity towards his other children, Isaac was the sole heir.

In Galatians 4:21-31, however, Paul is making a comparison between the sons of Abraham according to the law: Isaac and Ishmael. Abraham is the father of both Isaac and Ishmael; their differences lie in the identity of their mothers. One was born of the freewoman through promise, and the other was born of the bondwoman according to the flesh; these things are an allegory for something spiritual.

These two births symbolize two covenants—one from Mt.Sinai, which bears children to bondage, the other from the Jerusalem above that is free. Just as Ishmael scoffed at Isaac, so those born according to the flesh persecute those born according to the Spirit.

            [F]or this Hagar is Mount Sinai in Arabia, and corresponds to Jerusalem which now is, and is in bondage with her children—but the Jerusalem above is free, which is the mother of us all. (Gal 4:25, 26)

There are two Jerusalem’s, one that is physical and the other that is above. In the same way, there are two mothers. The Jews who did not believe in Christ were born of Hagar, represented by the Jerusalem at that time. Those born of Sarah, represented by the Jerusalem above, comprised the church at that time.

When Sarah gave birth to Isaac, she was not fertile, while Ishmael was born through Hagar’s fertility. In the same way, children born of the gospel are born through extraordinary means:

            “Rejoice, O barren, You who do not bear! Break forth and shout, you who are not in labor! For the desolate has many more children Than she who has a husband.” (Gal 4:27)

In this extraordinary way, Paul, who had no wife, could bear children in the gospel, “for in Christ Jesus I have begotten you through the gospel” (1 Cor 4:15).

Those born through extraordinary means, born of those who do not appear to be fertile, are children of promise. “Now we, brethren, as Isaac was, are children of promise” (Gal 4:28).

The Mother of Promise: the Church

It is clear from this passage that the critical determining factor of whether we are of promise or of the flesh is the identity of our mother. Paul writes that the Jerusalem above is the mother of promise.9 What characterizes the mother who bears the children of promise?

            “But you have come to Mount Zion and to the city of the living God, the heavenly Jerusalem, to an innumerable company of angels, to the general assembly and church of the firstborn who are registered in heaven, to God the Judge of all, to the spirits of just men made perfect, to Jesus the Mediator of the new covenant, and to the blood of sprinkling that speaks better things than that of Abel.” (Heb 12:22-24)

The heavenly Jerusalem is also MountZion, the city of the living God; she is the mother of the promised children. This place contains six things: angels, the general assembly, church of the firstborn, God the Judge of all, spirits of perfect men, Jesus the mediator, and the blood.

From this passage, the mother that bears children according to promise is the church of the firstborn, containing the general assembly of saints, chosen before the foundation of the world to be holy and without blame.10 She is the bride of Christ.11

For us today, MountZion, the city of the living God, is the church.

Is there only one church of the promise?

However, if we look around, we will see that there isn’t just one church. In fact, there are many different Christian denominations. There are many churches. Is there just one church that will lead to salvation, or will all these churches lead us to salvation? Why can’t we agree to disagree, and let things be?

            And He put all things under His feet, and gave Him to be head over all things to the church, which is His body, the fullness of Him who fills all in all. (Eph 1:22, 23)

            There is one body and one Spirit, just as you were called in one hope of your calling: one Lord, one faith, one baptism; one God and Father of all, who is above all, and through all, and in you all. (Eph 4.4-6)

            “For as the body is one and has many members, but all the members of that one body, being many, are one body, so also is Christ. For by one Spirit we were all baptized into one body—whether Jews or Greeks, whether slaves or free—and have all been made to drink into one Spirit.” (1 Cor 12:12, 13)

These passages tell us that the church is the body of Christ, and that there is only one body. This body is composed of many members—each member is a Christian who has been baptized into the body, drinking of one Spirit. God declares in the Bible, unequivocally and indisputably, that the body of Christ is the church, and that Christ has only one body. As such, we simply believe in God’s words.

Inconveniently, this poses a problem for us: there are many churches who profess Jesus Christ as their Savior and head, yet, the Bible tells us there is only one body. This brings us back to the story of Abraham, Ishmael, and Isaac.

Abraham had a similar conflict: he had two sons, and God chose only one son. He loved Ishmael, but God made it clear that He would be establishing his covenant exclusively with Isaac.12

Even though Abraham, as Ishmael’s father, may not have understood the reasons why God chose Isaac and not Ishmael, he still obeyed God, and sent Ishmael away.

Likewise, although there are many Christian churches, there is only one true church according to God’s promise that will inherit salvation. We may feel that it is more Christian to agree to disagree and just say that every church is of God’s promise and will lead us to salvation. This is a temporary fix that will optimize harmony, yet no amount of harmonizing can distract from the Bible’s words: the church is the body of Christ, and He has only one body.

Only the true church will bear children according to promise and inherit eternal life. Just as in the story of Abraham, the reason why Ishmael was sent away wasn’t because he was mocking Isaac; the reason Ishmael was sent away was because he was not to have any part in Isaac’s inheritance.

Just as this confounded Abraham’s paternal instinct, it confounds our inclusive instinct to believe in one true church. Yet, just as Abraham submitted to God’s word, we ought to submit as well.

Let us not be mistaken, though. Did Abraham love Ishmael? Yes, he did. Does God love all the Christians in the world? Yes, He does.

In fact, God loves everyone in the world, because fundamentally, we are all His children. We are all descendants of Adam, who is the son of God.13 God causes the sun to shine on the righteous and the wicked; He does not withhold sunshine and air from anyone, even sinners.

God loved Ishmael, even though he was not born according to God’s promise, because he was Abraham’s son. We can see later on that God took very good care of Ishmael, and made him the father of nations.14 Abraham was Ishmael’s father, and if Ishmael called out “Father!” then Abraham would reply.

In the same way, today there are many churches who call God their Father, and indeed, God hears everyone’s prayers. God’s love is not limited solely to the one true church. The difference is, not all the churches are born of promise. Some are born of the ordinary way, from the bondwoman, yet only one is born of the Spirit.

Finding the church of promise

How can we discern which church is the one born of the promise? Whether a church is born of promise is not something the church can self-proclaim; such a claim needs to be approved by God. The Bible tells us how to discern the church of those born of promise.

            Jesus answered and said to him, “Most assuredly, I say to you, unless one is born again, he cannot see the kingdom of God.” (Jn 3:3)

            Jesus answered, “Most assuredly, I say to you, unless one is born of water and the Spirit, he cannot enter the kingdom of God.” (Jn 3:5)

Jesus tells us that if a person is not born again, he cannot see the kingdom of God. He further says that if a person is not born of water and the Spirit, he cannot enter the kingdom of God. It is of utmost importance to be born of water and the Spirit. What does that actually mean?

Born of the Spirit

The kingdom of God is in this world, and is comprised of those who are born again of water and the Spirit. The prophet Joel wrote that God will pour out His Spirit to those in the flesh.

            “And it shall come to pass afterward that I will pour out My Spirit on all flesh; Your sons and your daughter shall prophesy, your old men shall dream dreams, your young men shall see visions. And also on My menservants and on My maidservants I will pour out My Spirit in those days.” (Joel 2:28, 29)

Jesus instructed His disciples to remain in Jerusalem until they were baptized with the Holy Spirit.15 They prayed in Jerusalem and received the promised Holy Spirit, described in detail in Acts chapter 2. This is the baptism of the Spirit.16

Paul writes that the Holy Spirit bears witness that we are the children of God,17 and is the guarantee of our habitation in heaven.18 In the same way that we demand a deed when we come into possession of a property, the Holy Spirit is the guarantee of our inheritance:

            “In Him you also trusted, after you heard the word of truth, the gospel of your salvation; in whom also, having believed, you were sealed with the Holy Spirit of promise, who is the guarantee of our inheritance until the redemption of the purchased possession, to the praise of His glory.” (Eph 1:13, 14)

The Holy Spirit verifies that we are the promised children of God, and thus heirs to the inheritance that is prepared for us. The baptism and rebirth through the Holy Spirit is something that each and every one of us can experience, just as the apostles did on the day of Pentecost.

Born of Water

After the apostles received the Holy Spirit, Peter got up and preached the gospel. The word of God pierced the hearts of all the listeners. They were determined to embrace Jesus as the Lord and Christ. What happened then?

            Now when they heard this, they were cut to the heart, and said to Peter and the rest of the apostles, “Men and brethren, what shall we do?” Then Peter said to them, “Repent, and let every one of you be baptized in the name of Jesus Christ for the remission of sins; and you shall receive the gift of the Holy Spirit. For the promise is to you and to your children, and to all who are afar off, as many as the Lord our God will call. (Acts 2:37-39)

Peter did not indicate that when the people believed, their sins were forgiven. Our sins are not forgiven when we believe. When we believe, we begin the process by accepting Jesus as our Savior.

As Peter indicated above, our sins are cleansed after we are baptized in the name of Jesus Christ. This is what it means to be born of water. When our sins are washed away, we are reborn as sons of God:

            “For you are all sons of God through faith in Christ Jesus. For as many of you as were baptized into Christ have put on Christ. There is neither Jew nor Greek, there is neither slave nor free, there is neither male nor female; for you are all one in Christ Jesus. And if you are Christ’s, then you are Abraham’s seed, and heirs according to the promise.” (Gal 3:26-29)

The Church of Promise

Thus, a church is of the promise if it is comprised of people who are born of water and the Spirit; that is, they have received baptism for the remission of sins and received the Holy Spirit to prove that they are the children of God.

Some churches do not believe that baptism has the power for the remission of sins. Many people believe that simply believing in Christ is enough to be saved. While simply believing is a good start, it is not complete.

We need to seek out the church that has the complete truth, with the baptism for the remission of sins, with the abidance of the Holy Spirit. Only such a church will lead you completely to the Lord.19

The True Jesus Church is such a church. The baptism in the True Jesus Church has the power to cleanse sins, because the church has received the promised Spirit, who has the authority to forgive sins. Signs and miracles during baptism confirm the efficacy of water baptism for the remission of sins.

The promised Holy Spirit abides in the True Jesus Church, just as it is described in Acts 2. Our members have the promised Holy Spirit, experiencing it in the same way the apostles did on the day of Pentecost. In the True Jesus Church, we can be born of water and the Spirit, enabling us to see and enter the kingdom of God. There is one Spirit, one baptism,20 and both are contained in the True Jesus Church.

To receive baptism in the True Jesus Church is to be born of the mother of promise. She is the freewoman, Sarah, whose offspring are the heirs to God’s promise. Other churches who do not baptize with the baptism that washes away sin, and do not have the promised Holy Spirit, bear the children of the bondwoman. She is Hagar, who gives birth by ordinary means.

The children borne by Sarah and Hagar are all loved and cared for by Abraham, and despite how well they may harmonize with one another, in the end, only the children borne of Sarah will be the heirs of Abraham’s inheritance.

God showers His love and blessings on all the followers of Christ, but only the children born of promise, born of water and the Spirit, will ultimately inherit eternal life.

Now, only one question remains: which mother are we born from? If we are children born in the True Jesus Church, we must have a heart of thanksgiving. Like Isaac, it is not by any doing of our own that we are born as an heir to God’s promise. It is purely by God’s choosing and mercy.

If we have not yet been born in the True Jesus Church, let us humbly seek to understand the correct path of salvation so lovingly laid down by our Lord Jesus Christ. Then, being borne of God our Father, and the True Church our Mother, we can be heirs to His great and mighty promise.


1.        Gen 16:3

2.        Gen 17:19

3.        Gen 16:11

4.        Gen 18:13

5.        Gen 21:6

6.        Gen 21:14

7.        Gen 21:20, 21

8.        Gen 25:1, 2

9.        Gal 4:26

10.     Eph 1:3, 4

11.     Rev 21:2

12.     Gen 17:18, 19

13.     Lk 3:38

14.     Gen 21:13

15.     Acts 1:5

16.     cf Acts 11:15, 16

17.     Rom 8:15-17

18.     2 Cor 5:4, 5

19.     Jn 20:22, 23

20.     Eph 4:4, 5