
Dr. Michael Barber and Dr. James Prothro, professors of Sacred Scripture at the Augustine Institute Graduate School, study St. Paul's pivotal Letter to the Galatians.
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A
Hello, I'm Michael Barber, and this is my dear friend Dr. Jim Prothero. And we're here for our Bible study on Galatians. We're having a blast working through this amazing Epistle of St. Paul. We're going to pick up now in chapter four, where Paul says, tell me, you who desire to be under the law, do you not listen to the law? For it is written that Abraham had two sons, one by a slave woman and one by a free woman. So let's just stop here for a second and talk about the backstory here. Abraham had two sons. And what do people need to know about those two sons?
B
Yeah. So back in the book of Genesis, Starting in chapter 12, when God first called, Abraham promises Abraham that he's going to have a family and that through his family, the whole world will be blessed. We talked about this a little bit in Galatians 3. But if you follow along with that at first, Abraham is. He's always trusting God. He's following God. And yet in Genesis 15, he says, God, you haven't given me anybody yet. God says, you own son shall be your heir. And Abraham and his wife Sarah, they're both old, past the point where either of them should expect to be able to father a child. It would be miraculous anyway. And Sarah has a handmaid that is say, a slave girl, right, who's under her. And she says, you know, I'm putting words into her mouth. She thinks, well, maybe God didn't mean through me, right? Let's try it with this younger.
A
I've always thought that I've always had in mind Abraham taking the Benjamin Franklin approach. Well, God helps those who help themselves, right? And so I got to help myself figure out a way to have a son. And, you know, Sarah, it ain't working out, so what are we going to do? And she says, well, take my handmaid. And so Abraham, either one of these scenarios is a way to understand it, but he has a child through the handmaid.
B
That's right. And in Genesis, and Paul has got this in the background, right? The question is, God makes a promise. And does God make a promise? Meaning, okay, now, I promised you this, now go out and get it. Or. Or does he mean I promised you this? So wait and let me give it to you my way. So God has promised Abraham a great big family. Abraham then takes to wife Hagar, who is sort of like becomes and has a child by her, right? So the child of Hagar will count for Sarah's child legally. And yet both of them now are kind of in a wife or a sort of top wife and an underwife position because she's the servant to Sarah. And God says there's a lot more to the story where they fight with each other and everything like that. But God says, no, Sarah is the one through whom I will give you the covenant family, not Hagar, the slave woman. They took upon themselves to get God's blessing their way. And maybe it made sense to them, right? It was legal. This is a normal way of doing things that they go about. But God says, no, I promised you, so you let my promise be what I give you, right? And so finally, Abraham has a child named Isaac through Sarah, his wife, right? The aged wife. And then the two boys, though in the same house, kind of compete with each other. And that's where we're going to see Paul reference here to the point that Hagar and Ishmael still have a blessing from God not to be the covenant family, but they still get a blessing from God and Ishmael will become a great nation, but they have to leave because this family, right, and the business of God's promise has to remain founded on God's promise. And that means that it's going to come through the line of Isaac. And so being part of Abraham's family and the covenant family means being part of Abraham's family through Isaac, not just any child of Abraham. And Paul is going to be able to sort of extract some further meaning and illustration for the Galatians and for us as well from this as he interprets it for them.
A
So he says, but the son of the slave, and that would be Ishmael, right? So Hagar's son, not Isaac, the son of the slave, was born according to the flesh, while the son of the free woman was born through promise. And so what he's doing here is he's identifying Isaac as the promised child. The reason Isaac comes into existence is because God had promised Abraham a son. And the other child, Ishmael, is not the son of the promise. He happened to exist because of the will of the flesh, so to speak, right? Now this, he says, now this is a key passage. Now, this situation of the two women and their children, this may be interpreted allegorically. So symbolically, these women are two covenants. One is from Mount Sinai bearing children for slavery. She is Hagar. Now Hagar is Mount Sinai in Arabia. This is a really dense passage. There's a lot here. So what is Paul doing? Well, he's saying, well, you know, Hagar eventually is cast out and she set out into Arabia. And Ishmael is associated with the Arabians going forward in the. In the biblical story, Mount Sinai, which is where Moses received the Torah, right? Mount Sinai is in Arabia. So Paul's linking all of these things together. And he says, now Hagar is Mount Sinai in Arabia. She corresponds to the present Jerusalem, for she is in slavery with her children. So now, Ab, you have Ishmael and Hagar associated with the present Jerusalem and associated with Mount Sinai, where the law of Moses is given and Jerusalem is now in slavery. What does that mean? We'll come back to it in a second. And then he says, but the Jerusalem above is free, and she is our mother. For it is written, rejoice, O barren one who does not bear. Break forth and cry aloud. You who are not in labor for the children of the desolate one will be more than those of the one who has a husband. All right, let's finish the passage, and then we'll unpack it a little bit. All right? Then he goes on to say, now you, brothers, like Isaac, are children of promise. But just as at the. Sorry, but just as at that time, he who was born according to the flesh, that's Ishmael, the son of Hagar, just as that child persecuted him who was born according to the spirit. And we read about this in Genesis. It says that Ishmael was playing with Isaac. But Jewish interpreters, Christian interpreters, saw that idea of playing with him. It's kind of like taunting him, toying with him. Obviously, Ishmael is jealous of Isaac. And he's the older brother, the stronger brother. His father's old and decrepit. The plan may be for the father to give the inheritance to this younger son. But if the father dies, he is the child of the promise is going to be at the mercy of Ishmael. And so what ends up happening is, of course, we read next, Ishmael was persecuting the one who was born according to the Spirit. So also it is now. But what does the scripture say? Cast out the slave woman and her son, for the son of the slave woman shall not inherit with the son of the free woman. That's from Genesis 21. This is what happens in Genesis 21. God tells Abraham, you have to send Hagar and Ishmael away. It's heartbreaking scene. But what's going to happen if Ishmael stays? It ain't going to be good for Isaac once Father Abraham passes away. If Ishmael realizes, well, I only get the inheritance if he dies. We can accelerate that process. Right? So, brothers, we are not children of the slave, but of the free woman. All right, what I'd like to do is, in just the next few minutes here, unpack this passage, because there's so much that we can talk about here. Where would you like to start?
B
Oh, goodness.
A
Yeah.
B
So I think it's helpful in this passage here to start at the end, because Paul gives his sort of final conclusion in verse 31, right? And this is something that he's argued earlier and proved earlier. And he's going to reiterate it here as kind of think about it like bookends. But then we can see from there what he's trying to tell them to do in their context, and then we can think a little bit about what he's saying about salvation history.
A
This is why I wanted to read the whole passage so you can see where it's going.
B
Yeah, that was the right move. Yeah.
A
All right.
B
Yeah, that was much better. But if you look at verse 31, right. So, brothers, we are not children of the slave, but of the free woman. And why are we children of the free woman? What does that mean, children of the promise? What promise? Has he been talking about a promise? Well, yeah, that's the whole point of Galatians 3, right? Is that God promised Abraham, you will have a child, and from that child a family. And through that family and its one capital D descendant, Jesus Christ, blessing for the whole world. The whole world will be blessed in Abraham through Jesus. That's the line of promise. And God's promise. Are the Galatians being tempted to listen to God's promise and wait for his salvation, or are they going, oh, yeah, thanks for the Jesus promise, God, but now let me go and get it done myself, I'd be uncircumcised and doing all the right things. Right? So children of the promise, on the one hand, means that we're from this line, right? That we're Sarah's children and that in Christ we're part of Isaac and Abraham, ultimately part of Jesus, right, in this family. But then he's also going to be able to make other points, right? Because he said that already. He's also from that. And then from this illustration about the child of promise, he's going to be able to make points about what he wants them to do, how he wants them to treat the people who are insisting that they get circumcised, and then we can talk a little bit about his theology here, Right? Yeah.
A
So one of the key issues is that you have people in the churches of Galatia, as we've seen, who are advocating that the Gentiles be circumcised. And they represent those who are associated with the law. And so they're represented by Sinai and represented by the slave one. And what he's saying is, you don't want to be enslaved. You don't want to be in bondage here. And what I like to do is go back maybe to the beginning. So we just looked at the end of it. It's interesting how he introduces it. He says these women are two covenants. And I think that's key. So what I like to show people is this little chart here. And I don't know if you can see it, Dr. Parthur on my computer, but I've got. Basically, there are two covenants here. And this is from our book that I wrote with Brant Petrie and John Kincaid, Paul, New Covenant Jew, that the Old Covenant is associated with Hagar and with Ishmael, and so children for slavery, as Paul puts it, they're born according to the flesh. And it's associated with Mount Sinai, which Paul links to the present Jerusalem. And he links being under the law to a kind of slavery. And then there's the New Covenant. And the New Covenant is identified with Sarah, who's a free woman, Isaac, the son of the promise, born of the Spirit. So if you insist on being circumcised, what you're doing is you're putting your faith in the flesh quite literally, right? You're. You're doing something to your flesh. Where Paul says, what ultimately matters is not what you do with your flesh, but what happens in the Spirit, right? And so if you, a Gentile, try to take on the requirements of the Old Testament, of the Old Covenant, so to speak, you're going backwards rather than forwards. And that those in the New Covenant, as he says, are associated with the Jerusalem above, which also in the New Testament seems to be. The idea seems to be expressed in terms of a heavenly Jerusalem. And we can talk a lot about how Jewish apocalyptic works seem to envision that kind of heavenly realm. And whereas those who want to go back to the Old Covenant are associated with being under the law and under slavery in Christ and in the Spirit, we're free. We're free, of course, not just from having to keep all the Old Testament requirements like circumcision for Paul, but we're also free from sin, free to live a new life in Christ anyway.
B
Yeah, no, I think that's really good. And there's a couple of points that I think are worth bringing up here. One of them, when you read through this allegory, right, and you think about Mount Sinai and the law, on the one hand, this seems really harsh. This is not the way that I think of it. When I read Exodus, I usually think, like Moses, yay, God's ten commands, right? Hey, here we go, right? So some people have come to this passage and said, oh, see, Paul, he quotes it once in a while because it's God's word, I suppose. But really, Paul wants all of the Christians, at least the Gentile ones and certainly me, to just throw that Old Testament out. And so one thing that is helpful to point out here, actually a couple of things. So first of all, looking at verse 21, what's Paul appealing to? What's Paul resting the authority of what he says on the law, right? That is, say, the first five books of Moses. When we talk about the law, see here we can be thinking about the books of the Old Testament, which Paul uses all the time in quotes. And he says the Ten Commandments are good. He quotes them in Romans, right? He says they're fulfilled in Jesus. The Holy Spirit fulfills them in us through charity and love and faith, working through love. And back in chapter three, he says, in three, 21, is the law opposed to God's promises? Is it law against promise? No, it's not. He says God gave the law on purpose for a good reason. But now that the Son has come and we are given the inheritance, then it's the Son to whom we look for our relationship with God and not just the law system. And when you come Back to Galatians 4 here, you can think about it. I think this way, right? When Paul's looking back on history and kind of what God is up to, the law is not against the promises. The law is good. It was good for Israel. It helped people prepare for Jesus. It didn't save them, but it doesn't. A code of text doesn't save anybody. It's God who saves. But then what's going on here in chapter four, he's talking about them being parallel at the same time, right? Are you going to follow Jesus or are you going to run over to the law? Up to the point of Christ coming, you're supposed to be under the law. Everybody's under the law. That's the divine plan. But then when Jesus comes, you're supposed to go, okay, I still read these. These still teach me about God and my faith, but my salvation, my relationship with God and how I have become God's Son is now difference, not just circumcision that brings me into this family or even my physical birth, being a descendant of Isaac, it's actually my birth, birth in the Spirit. But in Galatians 4, when he says, look, throw them out, cast out the slave woman, right? It's because people are putting them in competition. It's not the problem with the law, it's the problem with what people do with it that Paul is getting at.
A
Right. And Paul will even say in Romans, the law is spiritual. Yeah, Right. So obviously doesn't think the law is in and of itself a problem. But one of the things that we've seen in Galatians is that the law itself is not capable of enabling you to keep its commandments. The law itself is not capable of transforming you. Again, I love that famous expression of Augustine. Right. Basically, the law was given, so grace we'd seek, and then grace was given, so the law we could keep. Right. That is, I think, underlying a lot of what Paul is doing here. All right, so one big takeaway for me in looking at this passage is that we are constantly confronted with the temptation of, rather than trusting in the spirit, trusting in the flesh. And I think that Abraham himself is an example of that. Right. He ends up having a child through Hagar because he figures, it's all on me. I got to make this happen. And so much of my life, I don't know if you can relate to this, but so much of my life, I feel like, okay, I got to make this happen. It's all riding on me. It's riding on me articulating things the way I want so that I can convince somebody to hire me. It's all riding on me to get the work done. It's all riding on me to instill into my children the values and the morality that I want them to embrace and the priorities I want them to embrace. And it's really not all on me in the sense if, If. If I succeed, it's ultimately because of the Spirit. Right. And so I think we can fall into the same trap that the Galatians are tempted with. The. The circumcision party is making a pretty compelling case right there. In the Torah, it says that if you want to be part of the people of God, here's something real simple you can do. And what Paul is saying is, no, you don't need to do that, because now all Gentiles can be, you don't have to become an Israelite by being Circumcised now you can all be included in the people of God. That takes some trust, doesn't it?
B
It does, it does. And, you know, we have other things that we do where we trust in the flesh. And you can see these really clearly in other letters of Paul, too. We should do 1 Corinthians sometime. But it's really easy. It's really easy to hang our worth before God on things that don't come from God. And that really is the fundamental mistake, is that what we are to God, we are because he made us. What's lovable in us is lovable because he loves us. And it's really easy to play the one uppie game, right? Well, you know, I was baptized by bishop, so. And so I was baptized by the Pope, right? Which is a great grace and a great occasion, but it doesn't mean so much if you don't actually let the Holy Spirit given to you in baptism work in your heart. Right.
A
There are many saints who are not baptized by bishops.
B
That's right. That's right. There are a lot of little sort of checkpoints that we say, like, okay, well, and sometimes we mean this really sincerely, like, I'm still struggling with this. And we say that because we know our own sin and temptation, and that's good. Sometimes we use that as an excuse and we say, I don't know, that's just kind of one of my things. But I tithe. I say an our Father every night, and there's my baptismal certificate on the wall, right? So I'm good. And we go, well, that's like, those are all good things. That's maybe a little bit like the Pharisees standing there in the temple and saying, okay, God, here's the good things that I do. Here's a list. Look at those. Please don't actually look at my heart, Right?
A
Yeah.
B
Look at this other guy sins, Right? This tax collector.
A
Right? And the real lesson here is ultimately a lesson of faith, right? Where do you put your trust? Do you put your trust in the things that I can do, or do you ultimately put your trust in the Lord? And, you know, I probably said this before unformed, but I don't think I've said it with you. And if I have, I apologize. But one of my constant reminders of this is in parenting my children. I will react to them doing something I didn't want them to do. Oftentimes we say, well, why didn't you just listen to what I said? It's so obvious what you're supposed to do. And as I'm scolding them, I think to myself, and I do the exact same thing, right? And so now what I've, I've learned to habituate myself to do is the first, my first reaction to, you know, a behavioral issue or something like that in the house is sit down with my son or daughter and okay, let's try to retrace our steps. First thing. Did you pray today? Right. Did you ask God to help you today? Because I can often fall into that trap of, you should have just done this and this, and I need to help communicate to my children. You are not going to be successful in doing the right if you neglect the life of prayer and you neglect the fact that you completely need to depend on God and on his grace. And so, you know, for me, I come home from work and the first thing I do at dinner is, you know, how was your day? I say, all right, so who prayed what today? Did you say prayers? Did you say your prayers? And when you woke up, you know, Simon, did you say your prayers? He's for you. Yes, Daddy. Is that the truth? No, Daddy, but for me, that's just one practical way that this is evident. Do we really trust in the Lord to help us or do we see ourselves as basically lone rangers?
B
Yeah. And you know, the flip side of that too is, is, is letting God make promises to us and letting God tell us of his love.
A
Right.
B
It's really the, the flip side of the confident focus on the little things or the easy ticked boxes where we say, like, oh, I'm good because I have these few things. The flip side of it is to say, oh, I can see that I, you know, that I really do still struggle or I really do fail all the time. And then to go, oh, no. Right. And to fall into a kind of despair where God is whispering into our ear and saying, I love you. I know. My whole job that I want to do with you in saving you is to make you healthy. You don't have to be healthy to come in the door. You don't actually have to be healthy after the two week boot camp. You know, it's not like a Biggest Loser TV show. Like, well, good thing we brought all of you in. Come as you are. And then God says like, okay, now get on the training program. And then after two weeks, he's like, oh, you still committed one of those sins Out. Sorry, next contestant, just do that. But we have to faith, right? Faith is the openness to God's love and being ready to seek God both in. Right. Trusting him instead of ourselves when we're confident and trusting him instead of ourselves when we're despairing. And the voice inside of our own head is telling us that we shouldn't even talk to God because why would he listen? He loves to listen.
A
The other part of this is cast out the slave woman. Right. So what does that mean in context?
B
Well, so I mean, why does Paul cite that? Yeah. So Sarah is supposed to get rid of. Right. Hagar. Because Hagar's influence will. Or Ishmael, particularly the son. Right. Will have a bad effect on the line of promise.
A
I actually think that Ishmael might kill Isaac. I think he's a physical threat.
B
Bad effect was maybe an understatement. But what's the thing that might harm the faith of the Galatians that they need to stop their ears from or maybe run out of town? Well, these troublers. Paul's going to get. We're going to get there a little bit more in chapter five, too, where Paul's going to have some really hard words. Yeah.
A
Some strong words.
B
Strong words about getting them out of there. But remember, these preachers have come in into Galatia and they're telling them this Paul saying, run them out of town.
A
That's right.
B
But even if not, and even when they're gone, they've got to also cast out this kind of thinking from their hearts.
A
That's right. That's the key thing.
B
Yeah.
A
Yeah. Right. Finally, I'd like to just emphasize this whole idea that circumcision is associated with being according to the flesh. Obviously, circumcision is associated with the generative organ and is associated with lust and other things. In Jewish literature, and what many Jewish writers seem to have believed is that circumcision is an expression of, like, self control or it's a renunciation of carnal desire in some form. And so this is why Gentiles, of course. Right. Are so uncouth, because they don't practice this. And so they're licentious and they're immoral and all the rest. And in this immediate context, what Paul is trying to say is they may make it out to be that circumcision is this really holy, sacred thing. And if you just do this one thing, you're in like Flynn. But what Paul is saying is actually their minds are still stuck on the flesh, you know, so it seems to me in Paul's other letters and elsewhere in Galatians, Paul is emphasizing one major of the spiritual life, and that is in One way or the other, returning to the life of the flesh, which is in contrast, which is intention, with the life of the spirit. These two things are going to be presented to us as alternatives. So I think that in this immediate context, circumcision for Paul is associated with the flesh. And the flesh is a broad umbrella, right, for sinful passions. And there are a lot of things associated with circumcision. Oddly enough, this thing that is associated with the flesh has now become like a badge of spiritual superiority or something like that. And it's weird that that can actually happen in our own context today, that things that are meant to teach us to repent, things that are meant to teach us to turn away from sin, can somehow be distorted or perverted to sort of be a kind of spiritual, like, unholy talisman or something, you know? So I think of ashes on Ash Wednesday, for example. You know, people go get their ashes. They don't go to confession. Are they repenting of their sin? And I. I can fall into that trap myself where, you know, oh, I gotta go, Gotta go to church at Ash Wednesday, we forget the spirit of penitence that you're really meant to enter into there.
B
Yeah, that's right. That's right. Yeah. Where the. And it's important, like you said just now, right, that the. When you. That when Paul talks about the flesh in this kind of way, he's talking about, right. Sort of sinful passions.
A
Right.
B
It's not flesh versus spirit, like physical, very important versus kind of, you know, out there. Right. There's a lot of spiritual, physical things in our faith.
A
Right, right.
B
Ashes, fasting, Eucharist, baptism. Right.
A
Water.
B
Yeah. Well, like everything, right? We're body and soul creatures.
A
And there's a resurrection, and there's a
B
resurrection which will be spirit and body,
A
but
B
they're supposed to always go together. And when we use the one thing right, because our passions pull us away from the spiritual, and when I say spiritual, I mean capital S. Spirit, like the Holy Spirit in him, working in us, we run off to these other things and get overly focused on them, and then it becomes part of this world of sinful passions.
A
That's right.
B
Yeah.
A
Well said. All right, we're going to see how Paul develops this further in the next chapter. And we've got so much exciting material to get to. Hope you're enjoying our Bible study. Want to encourage you to take your Bibles out, preferably a ESV Catholic edition, and take a look at Galatians Chapter 5 before watching the next video. If you have time, and we'll talk to you then. Until then, may God bless your study of His Word.
Podcast: Catholic Bible Study
Host: Augustine Institute
Date: March 18, 2026
Episode Focus: Exploring Paul’s Allegory of Hagar and Sarah in Galatians 4:21-31
This episode features Dr. Michael Barber and Dr. Jim Prothero from the Augustine Institute Graduate School of Theology, diving deep into St. Paul’s allegorical use of the story of Hagar and Sarah from Genesis, as presented in Galatians 4:21-31. Through thoughtful exegesis, the scholars unpack Paul’s teaching on the two covenants, the contrast between “flesh” and “promise,” and the critical application for both ancient believers and Christians today. The tone is deeply theological but approachable, with an emphasis on how faith and trust in God’s promise, not human effort or adherence to the law, shape authentic Christian identity.
[00:00-04:21]
“Does God make a promise meaning, ‘OK, now, I promised you this, now go out and get it’? Or does he mean, ‘I promised you this, so wait and let me give it to you my way’?”
— Dr. Jim Prothero [02:05]
[04:21-08:52]
“If you insist on being circumcised, you’re putting your faith in the flesh quite literally.”
— Dr. Michael Barber [11:12]
[08:52-14:02]
“Are the Galatians being tempted to listen to God’s promise and wait for his salvation, or are they going, ‘Thanks for the Jesus promise, God, but now let me go and get it done myself’?”
— Dr. Jim Prothero [09:31]
[14:02-19:52]
“So much of my life, I feel like, OK, I gotta make this happen. It’s all riding on me... And it’s really not all on me, in the sense that if I succeed, it’s ultimately because of the Spirit.”
— Dr. Michael Barber [18:31]
[19:52-21:46]
“It’s really easy to hang our worth before God on things that don’t come from God... It doesn’t mean so much if you don’t actually let the Holy Spirit given to you in baptism work in your heart.”
— Dr. Jim Prothero [20:54]
[21:46-25:31]
“You are not going to be successful in doing the right if you neglect the life of prayer and you neglect the fact that you completely need to depend on God...”
— Dr. Michael Barber [22:33]
“You don’t have to be healthy to come in the door... Faith is the openness to God’s love and being ready to seek God...”
— Dr. Jim Prothero [24:04]
[25:31-26:40]
“Even when they’re gone, they’ve got to also cast out this kind of thinking from their hearts.”
— Dr. Jim Prothero [26:33]
[26:40-30:22]
“Things that are meant to teach us to repent… can somehow be distorted or perverted to sort of be a kind of spiritual, like, unholy talisman...”
— Dr. Michael Barber [28:40]
“We’re body and soul creatures... when Paul talks about the flesh... he’s talking about, right, sort of sinful passions.”
— Dr. Jim Prothero [29:34]
The hosts encourage listeners to read Galatians Chapter 5 in preparation for the next study, promising further insights into Paul’s teachings and continued reflection on life in the Spirit.
“Hope you’re enjoying our Bible study. Want to encourage you to take your Bibles out... and take a look at Galatians Chapter 5 before watching the next video.”
— Dr. Michael Barber [30:22]