
Dr. John Sehorn, Academic Dean of the Augustine Institute Graduate School of Theology, sits down with Fr. Isaac Morales, OP, a Dominican friar of the Province of Saint Joseph and Associate Professor of Theology at Providence College, to discuss Fr. Isaac’s book The Bible and Baptism: The Fountain of Salvation (Baker Academic). This episode recounts the relevance of the Old Testament to the Christian understanding of Baptism.
Loading summary
A
Welcome back to this formed book study on Father Isaac Morales's book, the Bible and the Fountain of Salvation, which, as you know, if you saw the first episode, is the first in a series that Dr. Tim Gray and I are editing for Baker Academic on a Catholic biblical theology of the sacraments. I'm really excited to be back here with you, Father, for this second episode in which we'll get to dive into the book and give you a sense of what Father is up to in here. I think it's going to be a really rich conversation seeing how the Bible can. Can deepen our understanding of the sacrament of baptism. So, Father, let's just. Let's just start with a little observation about the title, which is that it's simply called the Bible and Baptism. A beautifully straightforward title for a Bible.
B
Tells you what the book's about.
A
Nobody's going to be confused as to what this book is about, but, you know, when I turn to the table of contents, you've got 12 chapters in all, and four of them are devoted just to the Old Testament. And as I mentioned in the last episode, that might seem initially a little bit unexpected, right? Baptism, as we know, is something that we see in the New Testament that is undergone by Jesus himself, that's practiced in the early church. St. Paul writes about it in his letters. And of course, Father said that's how he got into this topic in the first place, was through studying Paul. So why have four chapters in the Old Testament when baptism doesn't actually appear in the Old Testament?
B
That's a great question. And I talk about it in the introduction to the book. One of the things that makes this book relatively unique is that there are a lot of books on baptism in the New Testament, and they all typically begin either with the Gospels or the New Testament or maybe with some Jewish precursors, you know, John the Baptist's baptism, Jewish ritual, washings. But you don't have much on the Old Testament, and there's an obvious reason for that. There's no explicit references to baptism in the Old Testament, but part of the point of the series and of this book in particular, is to have a fully biblical understanding of the sacred sacraments. And I mentioned in the first episode how the Rite of Baptism does this, right? It talks about the waters of creation, the flood crossing the Red Sea, all these beautiful Old Testament images that can inform how we think about and understand baptism. And it does that for a couple of reasons. The rite, that is, does that for a couple of reasons. One is that the New Testament itself draws on imagery from the Old Testament to talk about baptism. So for example, in the first letter of Peter, he compares baptism with the flood and talks about how eight were saved through water. And he says, now baptism, which corresponds to this, now saves you.
A
Right. That's pretty clear, isn't it?
B
It is pretty. It's fairly clear. We could talk about exactly how to interpret it, but it's clear that he's connecting baptism to the flood.
A
Right.
B
And the church fathers did this all over the place. If you read the fathers on baptism, they're frequently referring to the Old Testament, even relatively obscure stories like the cleansing of Naaman the Syrian, who had this leprosy. And he baptized himself seven times in the River Jordan and he came out clean. So the title of the book, it's an allusion to another book, a fantastic book from the 1950s by a Jesuit. Can't believe I said that. A Jesuit. I have great Jesuit friends. I'm kidding.
A
Much love towards Jesuit friends out there.
B
Yes, indeed. No, a great Jesuit scholar by the name of John Daniellou, who had this book, the Bible and the liturgy. And I leaned on that book a little bit at the beginning, particularly for thinking about which passages in the Old Testament I should look at. Danielu's book talks about the sacraments of initiation, baptism, confirmation and Eucharist, and it looks at all the different images that the fathers used to speak about it. So since I had kind of relied on him in part to get started, in fact, there's a beautiful quotation from his book. In the introduction of my book, I have epigraphs at the beginning of each chapter. And Danieli writes in the Bible and the liturgy, baptism was born in the land of Israel. We must interpret the material elements which it uses as a symbol according to the significance of these elements for the Jews of old. It is in a Jewish order of symbolism that we shall find the exploit explanation of baptism. And so that's why we look at the Old Testament, because the symbolic value of water is found, which is the material element found primarily in the Old Testament. This is a common worry among some Catholics, at least especially with respect to the Eucharist. When people say, oh, is it symbolic? And people say, oh, no, no, it's really Jesus body and blood. Yes, it is really Jesus body and blood, but under a symbolic. Well, there's a symbolic signification. And both elements are important, the symbol and the reality. And the symbol is to be found especially not exclusively, but especially in the language of the Old Testament. Jesus himself, when he instituted the Eucharist was alluding to texts from the Old Testament to the covenant that God had established with the Israelites on Mount Sinai, to Jeremiah's prophecy of forgiveness of sins. And so that's why it's so important to go back to these texts.
A
No, and it makes sense, too, right, that Jesus said, do this, which is why we use bread and wine, which is what he used. And presumably he didn't just do that for fun or kind of randomly or that's just what was at hand, but that he would be drawing our attention to the way in which he's giving us his body and blood under the appearances of bread and wine. Yeah, so, yeah, that's really interesting. Okay, I'm kind of sold because now that I think about the material element that is the key symbol in baptism, namely water. Boy, you're right. It's really everywhere in the Old Testament. In fact, I'm just remembering, and forgive me, Father, if this is in the book, and I've forgotten, but Tertullian, who was a writer in the early Christian church around the turn of the third century, so around the year, just before and after the year 200, is when he was active, wrote a little treatise on baptism. And I seem to recall there being a line about how basically the whole cosmos is sort of like, this is going to be. I don't mean this as a pun, but I'm going to say it. Saturated in water. That it's like everywhere we look in the Old Testament, the waters of creation, the flood, you mentioned the Red Sea, they really are all over the place. Okay, so. All right, so I can see how you might squeeze four chapters.
B
Well, another point about that is I don't remember that Tertullian passage. I don't think I have it in there, but I do have a text from Cyprian of Carthage, and in one of his letters, he talks about this passage from Isaiah 43 that talks about water, and he reads it as referring to baptism. So basically, and he says something to the effect of wherever water is in the Old Testament, it tells us something about baptism.
A
Well, and as you probably remember, Jerome tells us that Cyprian read Tertullian every day.
B
Oh, really?
A
I can. So we can trace it right there. He just called him the master or the teacher. He would say, bring me the teacher, and he would read from Tertullian each day. So that's. Oh, that's wonderful. Yeah. And I noticed, though, that instead of kind of organizing your chapters according to these specific events, like the flood or the Red Sea, or maybe specific passages like you mentioned one from. Actually, you mentioned a couple now from Isaiah. It was in episode one.
B
Right.
A
You told us you got Isaiah 12 and now Isaiah 43. But instead of that, these four chapters, I'll just read them, and I'd love to hear you comment on kind of what your thinking was here. What's going on here. Instead of looking at different passages or books of the Bible, you refer to different waters. The waters of life, the waters of death, the waters of freedom, and the waters of purity. Tell me about this Father.
B
Yeah, so I think I got that idea in part from Danielu's book and seeing how the Fathers interpreted these texts. And I just thought it would be a better organizing principle. I say in the book it's in some ways artificial because there's a lot of overlap. And some passages will have two or three or even all four of these images. But I thought it was a nice way to categorize them. So life. Water in the Old Testament is frequently a symbol of life. Think of the waters of creation, the river that flows out of Eden, given life to the garden and to the whole world. Death. Well, the death image I got actually from Paul, because Paul frequently speaks of baptism as a dying and arising with Christ. And so there are lots of passages in Scripture where water is seen as, I wouldn't say a source of death, but it's something that can bring about death. It's a dangerous thing.
A
Well, I mean, Jonah goes into the water and Hades.
B
Yeah, exactly. Right. He's in the pit, which is another word for Hades or Sheol or whatever you want to call it. The realm of the dead. The realm of the dead. Yeah. Or the flood destroys, you know, all living creatures except for the ones in the ark.
A
The Red Sea wipes out.
B
Exactly.
A
Pharaoh and his armies.
B
Right. But I'm glad you brought up the Red Sea, because that's, again, one of many examples where there's overlap. Yes, it destroys the Egyptians, but it's also the path to freedom. They walk through the waters into freedom. So that's the third chapter, the waters of freedom and then purity. Purity was a big concern for the ancient Israelites, both ritual and moral purity. And we might talk a little bit more about that. Well, later in this episode. I forget what we're doing at what point. So there were lots of rites in the Old Testament for making a person pure so that they could participate in the activity of the temple, because that's one of the primary things that purity had to do with. But then ancient Israelites Also spoke about a kind of moral purity. And there were certain really heinous sins that would make a person impure. Not in the sense that they couldn't go to the temple, but that if these sins piled up in the life of the people, God was eventually going to expel them from the land. And he did in 587. So, B.C. yes, B.C. of course. Yeah. Yeah. So those are just four really, I think, beautiful images. And another reason that I chose these four is that each of them appears somewhere in the New Testament in relationship to baptism. They're not the only four. There are others that the New Testament adds, but these are kind of the foundation for the symbolic value of the sacrament.
A
Excellent. Okay, that's great. Well, maybe if you're up for a father, we could actually dig into a couple examples of this in specific passages. And it would be fun not to just do maybe one that everyone's gonna be familiar with, like the flood or like the Red Sea. So where would you like to go?
B
Yeah, well, let's start with the waters of life. Because while we were talking about this this morning, as we were prepping for these episodes, how we don't think about how important water is, or usually we don't. Right? You can just flip out a faucet.
A
I'm thirsty suddenly. I'm not joking.
B
I mean, you can flip out a faucet and you've got water, no problem. Right. For people living in the ancient near east, in a desert place with no running water, you really valued water a lot more than we do. Or maybe not valued, but appreciated just how valuable it is more than we do. And there's a beautiful passage towards the end of the book of the prophet Ezekiel that uses. It's a beautiful image. So why don't we go ahead and read it? Okay. So this is almost the end of the book. Not quite. This is Ezekiel, chapter 47, and it's a fairly well known image. I imagine many of the viewers are probably familiar with it. But let's just read it. It's about 12 verses. So Ezekiel says, then he brought me back to the door of the temple. And behold, water was issuing from below the threshold of the temple toward the east. For the temple faced east. The water was flowing down from below the south end of the threshold. Threshold of the temple. That's a hard word to say. Threshold of the temple, south of the altar. Then he brought me out by way of the north gate and led me around on the outside to the outer gate that faces toward the east. And behold, the water was trickling out on the south side, going on eastward. With a measuring line in his hand, the man measured a thousand cubits. A cubit, in case you don't know, is basically the span from the elbow to the tip of the finger. So it's about 18 inches, depending on. Depending on how tall you are. Where was I? And then led me through the water, and it was ankle deep. Again, he measured a thousand and led me through the water, and it was knee deep. Again, he measured a thousand and led me through the water, and it was waist deep. Again, he measured a thousand. And it was a river that I could not pass through, for the water had risen. It was deep enough to swim in a river that could not be passed through. And he said to me, son of man, have you seen this? Then he led me back to the bank of the river. As I went back, I saw on the bank of the river very many trees on the one side and on the other. And he said to me, this water flows toward the eastern region and goes down into the Arabah and enters the sea. When the water flows into the sea, the water will become fresh. And wherever the river goes, every living creature that swarms will live. And there will be very many fish, for this water goes there, that the waters of the sea may become fresh. So everything will live where the river goes. Fishermen will stand beside the sea from En Gedi to Eniglaim. It will be a place for the spreading of nets. Its fish will be of very many kinds, like the fish of the great sea. But its swamps and marshes will not become fresh. There to be left for salt. I guess you need a little salt still. And on the banks on both sides of the river, there will grow all kinds of trees for food. Their leaves will not wither, nor their fruit fail. But they will bear fresh fruit every month because the water for them flows from the sanctuary. Their fruit will be for food and their leaves for healing. Wow.
A
There's a beautiful passage.
B
There's so much we could say about this passage.
A
Could I start by asking you three questions?
B
Okay.
A
Okay. Just to kind of orient ourselves. First, who is the man who's leading Ezekiel around? Like. Like, what's going on with that?
B
I believe that's one of God's angels who's just showing him this vision. And it's.
A
So that was my other question. This is not a historical thing that.
B
No, no. This is a vision that Ezekiel has, and it's a symbolic promise. So the whole last part of Ezekiel is this promise to the Israelites who at this point, many of whom, if not all, are already in exile in Babylon after Jerusalem has been destroyed in 587 B.C. and so the Lord promises them he's going to bring them back, he's going to redeem, restore them. And so this is a beautiful vision of what that will look like. And the key is life. This water gives life. But the thing that I love about most about this passage is that the source of the life of the water of life is the temple. Because the life water only has life giving properties because God gave it those life giving properties. Now that doesn't mean that it's insignificant. Again, I'm going to turn on my Thomist hat. It's a secondary cause here. You know, God works through instrumental causes, they're real causes, but their power comes ultimately from the Lord himself.
A
Yeah, yeah. And this, I mean, it seems like not just like there's so many images of like abundance in here. Right. And I'm always kind of moved by this passage, how it starts as almost like a trickle. It's ankle deep, and then it's knee deep, and then it's waist deep, and then you can swim in it. It's like more and more and more. And it seems to have maybe not supernatural, but pretty remarkable life giving powers. Now it says that it's flowing east into the sea. What sea is being talked about here?
B
Presumably it's talking about the Dead Sea, right? This salty sea that you can't. I mean, nothing can live in it. Right?
A
Wow.
B
Or at least for the animal life.
A
So this is like life from the dead.
B
Yeah, exactly. Yeah.
A
Wow. Okay, that's really amazing. And it comes from the temple, right? The place where God dwells.
B
Yep.
A
Okay.
B
And then the other thing that Ezekiel is doing is that of course he's alluding back to the Garden of Eden. This is the image of the river of life, right? In the garden. The river goes out and gives life to things. So it points backwards. It also anticipates what we see at the end of the the Bible. In the book of Revelation, you have this beautiful image of the river going out and giving life to everything.
A
Okay, I gotta see this. This is, this is Revelation 22, 21 and 22.
B
I forget I should know. But it's.
A
Oh, you know what my little title at the top of Revelation 22 says the river of Life.
B
There it is. Perfect. Yeah. Do you want to read that for us?
A
Sure. Yeah. Then the angel showed me the river of the Water of Life. Okay.
B
All right.
A
You're not making it up.
B
Fire.
A
Yeah. I'm not. Bright as crystal, flowing from the throne of God and of the Lamb. Right. So the place where God dwells is where the water comes from, through the middle of the street of the city. Also on either side of the river, the tree of life with its 12 kinds of fruit yielding its fruit each month. Just like we saw at the end of that passage. You read, the leaves of the tree were for the healing of the nations,
B
which is exactly what Ezekiel says. That's exactly for healing, for food and for healing.
A
Boy, that's really powerful. Right. When we think about how much need for healing we see in the nations, and that this water that comes from God can actually provide that healing in that life.
B
Yeah. And then there's one other beautiful passage in the New Testament that draws on this in the Gospel of John, which is another. Well, it's a nice connection, because in the Gospel of John, John frequently portrays Jesus as a new temple. He is the temple of God's presence. And so when Jesus dies on the cross, the centurion pierces his side with a lance and out flows blood and water.
A
And water.
B
Right. The water pouring forth from the temple and giving life and healing to those who need it, which is all of us.
A
Yeah.
B
Oh, wow.
A
That's amazing. That's beautiful. Okay. Wow. Well, there's more to talk about, I'm sure, with Ezekiel 47, but you want to do one more passage.
B
Yes. We'll have to be brief on this one, but that's all right. Look at Ezekiel 36. And this is related to the question of purity. Might have to condense the reading. I'll read about six or seven verses. So in Ezekiel 36, beginning in verse 22, so Ezekiel says, therefore say to the house of Israel, thus says the Lord God. It is not for your sake, O house of Israel, that I am about to act, but for the sake of my holy name which you have profaned among the nations to which you came. And I will vindicate the holiness of my great name which has been profaned among the nations, and which you have profaned among them. And the nations will know that I am the Lord, declares the Lord God. When through you I vindicate my holiness before their eyes, I will take you from the nations and gather you from all the countries and bring you into your own land. I will sprinkle clean water on you, and you shall be clean from all your uncleannesses and from all your idols. I will cleanse you, and I will give you a new heart. And a new spirit I will put within you, and I will remove the heart of stone from your flesh and give you a heart of flesh. And I will put my spirit within you and cause you to walk in my statutes and be careful to obey my rules. So here again, you have water imagery. I will sprinkle clean water on you and clean you from all your uncleannesses. So the main thing, as I mentioned earlier in this episode, about impurity is that it kept somebody from worshiping the Lord in the temple. And as we saw in Ezekiel 47, the temple is the source of life. So it's not good to be impure
A
because you're see that overlap that you mentioned there, too. Right. This isn't some separate thing from.
B
No, they go together. Closely together.
A
Yeah. That's interesting. You say that the uncleannesses keep you from worshiping because then he goes on and says, from all your idols. We wouldn't usually think of idols as something that besmirches or dirties you.
B
Right. Well, not literally, you know, but interiorly, of course. And we all have our idols, sadly.
A
Yeah. Okay. Can I ask you one more question about this passage? I know you said you want to be brief on it.
B
Sure, yeah.
A
Yeah. There was a big emphasis in the first part of it. He says, it's not for your sake that I'm about to act, but for the sake of my holy name. And he talks about his name being profaned among the nations. What's going on there? I mean, it sounds a little bit harsh, like, I'm doing this for you. I'm doing it for myself, for the sake of my name. What's happening here?
B
Well, so what he's saying there is that the Israelites, who God entered into a covenant relationship with, which is frequently compared to marriage, they basically committed adultery. Right. That's what idolatry is. It's going after other gods, even though the Lord is the one who had freed them from Egypt, freed them from their slavery, given them a land, made his dwelling with them. And so the nations are saying, these are the Lord's people. They sure don't act like it and sure makes them look bad.
A
Right.
B
And I mean, sadly, we all do it to varying degrees. And so the point is that by purifying the Israelites and by giving them the power to actually obey, it's also going to clear his name. Now, these are not mutually exclusive things. It's actually our good is the Lord's good, and vice versa, his good is our good. So when he cleanses us when we can be in a relationship with him. It's obviously good for us because we're reconnected with the source of life.
A
Right.
B
And it also. The flow of life, but it also clears his name, as it were. And it's not as if God's word. Oh, no, my reputation, like God's doing all right on his own, you know, but it's for the sake of people not to think ill of him, because that's bad for us.
A
Right. Well. And so in that sense, when we don't let him cleanse us of our uncleannesses, of our idols, of the ways that we let his name be profaned among the nations, it's almost like we're getting in the way of the healing that we just felt he wants to
B
bring to the nations. Oh, yeah. Yeah. We're damaging ourselves.
A
Yeah. Wow. Okay. That's another really rich passage, but maybe this is a good place to bring this episode to a close. Any parting shots for me?
B
Well, just not for you. But just keep in mind the. Just think about the name. We'll talk about the name some more in another couple of episodes because it's a really important part of baptism as well.
A
Okay.
B
Yeah.
A
All right.
B
Sneak preview. Teaser.
A
Yes, we will look forward to that. And we hope you'll be able to join us next time for our third episode when we'll actually get to the New Testament. But I'm really grateful for this opportunity to look at the Old Testament and what we can learn about the great gift of our baptism that we've received in the church. So, Father, thank you for joining me again. We'll hope to see you next time. God bless.
Podcast Summary: Catholic Bible Study – "The Bible and Baptism: The Old Testament and Baptism"
Augustine Institute | March 2, 2026
This episode explores how the Old Testament lays a vital foundation for understanding the sacrament of baptism. Host A is joined by Father Isaac Morales to discuss Morales's book, The Bible and the Fountain of Salvation. The discussion focuses on why much of the book—and this episode—is devoted to Old Testament themes and imagery, despite baptism not being explicitly mentioned in those texts. Father Morales demonstrates how early Christians and Church Fathers drew on Old Testament passages to give richer meaning to baptism, highlighting four key symbolic uses of water: life, death, freedom, and purity.
"Baptism was born in the land of Israel. We must interpret the material elements which it uses as a symbol according to the significance of these elements for the Jews of old."
— B, referencing Daniélou, 03:54
"Yes, it is really Jesus [in the Eucharist], but under a symbolic... Well, there's a symbolic signification. And both elements are important, the symbol and the reality."
— B, 04:36
Father Morales chooses to structure the Old Testament analysis not by stories or books, but by the four symbolic types of water:
Waters of Life:
Waters of Death:
Waters of Freedom:
Waters of Purity:
"Each of them appears somewhere in the New Testament in relationship to baptism. They're not the only four... but these are kind of the foundation."
— B, 10:32
A. Waters of Life – Ezekiel 47
“The source of the life of the water of life is the temple. Because the life water only has life-giving properties because God gave it those life-giving properties.”
— B, 15:01
B. Waters of Purity – Ezekiel 36
God promises, while Israel is in exile, to cleanse the people with “clean water” and give them a new heart and spirit (18:48–22:25).
“I will sprinkle clean water on you, and you shall be clean from all your uncleannesses and from all your idols. I will cleanse you, and I will give you a new heart. And a new spirit I will put within you.”
— B, reading Ezek 36:25-26, 19:38
The need for purification to participate in divine life and worship.
The exile, disobedience, and idolatry of Israel are directly linked to the necessity for this new divine act of cleansing.
“By purifying the Israelites and by giving them the power to actually obey, it's also going to clear his name. Now, these are not mutually exclusive things. It's actually our good is the Lord's good, and vice versa... when we can be in a relationship with him. It's obviously good for us because we're reconnected with the source of life.”
— B, 22:02
“Wherever water is in the Old Testament, it tells us something about baptism.”
— B, referencing Cyprian of Carthage, 07:00
“It starts as almost like a trickle. It's ankle deep, then it's knee deep, then it’s waist deep, and then you can swim in it...more and more and more.”
— A, on Ezekiel 47, 15:47
“When we don't let him cleanse us of our uncleannesses, of our idols... it's almost like we're getting in the way of the healing that... he wants to bring to the nations.”
— A, 22:45
The episode is warm, conversational, and rich in scriptural insight. The hosts gently tease and build on each other’s knowledge, all while grounding the discussion in both ancient and contemporary Catholic thought. There’s an emphasis on how these Old Testament images speak not only to theological truth, but to the lived reality and hope of all Christians.
Listeners come away with a renewed appreciation for how richly the Old Testament prefigures and deepens our understanding of baptism. The episode sets the stage for further study of New Testament texts, emphasizing that every baptism points back to the story of salvation history and God’s ongoing work of renewal, transformation, and healing.
Next Episode: The hosts will move into the New Testament to show how these Old Testament foundations are fulfilled in Christ and the Church’s practice of baptism.