Episode Intro

How can God be one and three? How can Jesus be God and yet not another God? And what about the Spirit, where does he fit in?
In the last episode of Thinking Theology, we saw that God promised in the Old Testament that a day would arrive when he would come in person to save his people and be with them. But astonishingly, that happened in the coming of the man Jesus. Jesus did all the things that only God himself does like creating the world, miracles and forgiving sins. Jesus showed himself to be God, distinct from the Father. But how does that work?
That’s what we’re thinking about in this episode of Thinking Theology. We’re thinking about the Trinity—one God in three persons.

Podcast Intro

Hi. My name is Karl Deenick. I write about theology and I teach it at Sydney Missionary and Bible College. Welcome to Thinking Theology, a podcast where we think about theology, the Bible and the Christian life, not just for the sake of it, but so we can love God more, with all our heart, soul, mind and strength.

The Trinity in the Old Testament

As we read the Old Testament, again and again we find affirmations of God’s oneness.
The most famous of those is Deuteronomy 6:4.
4 Hear, O Israel: The LORD our God, the LORD is one. (Deuteronomy 6:4 NIV)
That statement became absolutely foundational to the Jewish people. There was only one God. Not two.
The significance of the Lord being “one” is explained by the following verse,
5 Love the LORD your God with all your heart and with all your soul and with all your strength. (Deuteronomy 6:5 NIV)
That is, there is but one God. He is to be loved with our whole being. Our love is not to be divided among other “gods”.
So God says in the Ten Commandments,
2 I am the LORD your God, who brought you out of Egypt, out of the land of slavery. 3 You shall have no other gods before me. (Exodus 20:2–3 NIV)
And we find many similar affirmations in the Old Testament that there is no God but one. So Isaiah 45:5,
I am the LORD, and there is no other; apart from me there is no God. (Isaiah 45:5 NIV)
Or Isaiah 45:14,
Surely God is with you, and there is no other; there is no other god. (Isaiah 45:14 NIV)
In other words, the basic conviction of the Old Testament is that there is one God. There are other fake gods that people have invented. But there is only one true God and him alone.
As the theologian Fred Sanders notes,
Read left to right from cover to cover, the Bible depicts a monotheism that turns out to be Trinitarian monotheism, not an initial threeness that turns out to be unified.
Nevertheless, even in the Old Testament there are glimpses or hints of the Trinity. So, for example, the very first chapter of the Bible says,
2 Now the earth was formless and empty, darkness was over the surface of the deep, and the Spirit of God was hovering over the waters. (Genesis 1:2 NIV)
That is, in the second verse of the Bible we have a reference to the Spirit of God.
Then in verse 26 and 27, we read,
26 Then God said, “Let us make mankind in our image, in our likeness, so that they may rule over the fish in the sea and the birds in the sky, over the livestock and all the wild animals, and over all the creatures that move along the ground.” 27 So God created mankind in his own image, in the image of God he created them; male and female he created them. (Genesis 1:26–27 NIV)
It has sometimes been suggested that the “us” here is a heavenly council—that is, God speaking with the angels—or that he is speaking to creation itself. But v. 27 excludes those possibilities since God makes humanity in “his own image” and “in the image of God”. Others have suggested that it is a plural of majesty—like the King of England saying “we” to mean just himself. But we don’t find that kind of expression used anywhere else in the OT. Instead, as the Bible commentator Andrew Steinmann notes, “the text clearly depicts God as an inward plurality and outwardly singular—our image … his image (vv. 26–27)….”
Later in Isaiah 63:9–10 we find another hint. There, in the same place, we find Yahweh, the angel of his presence and the Spirit. It says,
9 In all their distress he [Yahweh] too was distressed, and the angel of his presence saved them. In his love and mercy he redeemed them; he lifted them up and carried them all the days of old. 10 Yet they rebelled and grieved his Holy Spirit. So he turned and became their enemy and he himself fought against them. (Isaiah 63:9–10 NIV)
Now we need to be careful not to overplay these hints in the Old Testament. It would be wrong to suggest that an Old Testament Israelite could have unpacked the full doctrine of the Trinity from these hints.
But looking back these pieces make total sense.
As we saw last time, the Trinity in the Bible is like a murder mystery. The clues are all there on the first read through. But it’s not until you get to the end and find out who did it, that you can go back and see all the clues for what they are. It’s not that the clues weren’t there. Nor is it that the clues have been invented after the fact and made to say something more than they were intended to say. Rather, it’s just that without the key, without the solution to the riddle, the clues don’t yet make sense.
Or as the theologian B. B. Warfield once described the doctrine of the Trinity in the OT, it’s like a “chamber [or a room] richly furnished but dimly lit.” There are allusions and hints, but it is not until the coming of Jesus and the Spirit that we fully apprehend the Trinity.
Again, to quote the theologian Fred Sanders,
The doctrine of the Trinity did not arise and cannot stand without the Old Testament, but the Old Testament’s usefulness for Trinitarianism is retrospective and dependent on the light provided by the fullness of revelation. We cannot set aside the Old Testament, but we can put it off until the salvation-historical mystery of the Trinity has emerged and the light of the New Testament has arisen.

The Trinity in the New Testament

And so it’s unsurprising to see that those ideas of oneness and threeness continues in the New Testament.
For example, when Jesus is tempted by Satan in the wilderness in Matthew 4:10, he quotes Deuteronomy 6:13,
10 Jesus said to him, “Away from me, Satan! For it is written: ‘Worship the Lord your God, and serve him only.’” (Matthew 4:10 NIV)
In other places, too, the conviction of “one God” is affirmed but with additional complexity. For example, Paul seems to riff off Deuteronomy 6:4 when he says in 1 Corinthians 8:5–6,
5 For even if there are so-called gods, whether in heaven or on earth (as indeed there are many “gods” and many “lords”), 6 yet for us there is but one God, the Father, from whom all things came and for whom we live; and there is but one Lord, Jesus Christ, through whom all things came and through whom we live. (1 Corinthians 8:5–6 NIV)
Paul, there, echoes Deuteronomy 6:4, “The LORD our God, the LORD is one.” But he also affirms that the Father is this one God, and Jesus, too, is the same Lord.
Likewise, in Ephesians 4:4–6, Paul says,
4 There is one body and one Spirit, just as you were called to one hope when you were called; 5 one Lord, one faith, one baptism; 6 one God and Father of all, who is over all and through all and in all. (Ephesians 4:4–6 NIV)
And again in 1 Corinthians 12:4–6,
4 There are different kinds of gifts, but the same Spirit distributes them. 5 There are different kinds of service, but the same Lord. 6 There are different kinds of working, but in all of them and in everyone it is the same God at work. (1 Corinthians 12:4–6 NIV)
In both passages Paul puts the three persons in parallel—they are distinct—but he also emphasises their oneness—it is the same Spirit, same Lord, same God.
Finally, in various places in the New Testament, then, we also have formulas that put the three persons of the Trinity together on an equal footing. For example, Matthew 28:19,
19 Therefore go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit…. (Matthew 28:19 NIV)
And 2 Corinthians 13:14,
14 May the grace of the Lord Jesus Christ, and the love of God, and the fellowship of the Holy Spirit be with you all. (2 Corinthians 13:14 NIV)
But perhaps one of the most significant places where we see the Trinity is in baptism of Jesus. There we see simultaneously and distinctly, the Father and the Son and the Spirit.
So in Matthew 3:16–17 we read,
16 As soon as Jesus was baptized, he went up out of the water. At that moment heaven was opened, and he saw the Spirit of God descending like a dove and alighting on him. 17 And a voice from heaven said, “This is my Son, whom I love; with him I am well pleased.” (Matthew 3:16–17 NIV)
That event is important because we the three persons simultaneously. A heresy would later develop in the history of the church that God is not actually three persons, but he can appear in different masks. Sometimes he is the Father, sometimes the Son, sometimes the Spirit. But here we see all the persons operating at the same time. The Father in heaven speaking, the Son on earth being baptised, and the Spirit descending as a dove.
This appearance also brings to light a very important point about the doctrine of the Trinity. That is, that the place where the Trinity is most clearly revealed is in the persons of Jesus and the Spirit acting in the world in the New Testament.
It is the appearance of Jesus on earth as a man, doing the things that only God can do, healing, raising the dead, forgiving sins; it is that which demonstrates most of all that doctrine of the Trinity.
Similarly, it is the appearance of the Spirit at Pentecost and in the life of the church that shows most clearly the person of the Spirit.
So while it is helpful to look for verses that explain or show the theological conviction that God is one God but three persons—Father, Son and Spirit. We also need to recognise that the place we see the Trinity most clearly is in the actions of the Son and in the actions of the Spirit.

The Doctrine of the Trinity

So what ought we to believe about God concerning the Trinity?
1. There is only one God.
2. There are three distinct persons—the Father is not the Son or the Spirit, the Son is not the Father or the Spirit, and the Spirit is not the Father or the Son.
3. Those three persons are not three gods or three parts of God, but they exist simultaneously and completely as the one God. They are one essence or being.
4. Each of the persons have always existed. That is, there was not a time when the Son did not exist and was not the Son, or the Spirit did not exist and was not the Spirit. But God has eternally been three persons in one essence.
5. Each person is fully God and to be worshipped as God.
In understanding what the Trinity does and doesn’t mean, it can be helpful to consider some historical errors, particularly with respect to the Father and the Son.
The first wrong view is often called Arianism. In that view, Jesus is not God but just another creature through whom God works. That is the view of a man from the third century called Arius. It was condemned around that same time as a heresy. It is also the view of the Jehovah’s Witnesses.
The second wrong view is tritheism. That is simply the view that Jesus, the Father and the Spirit are different gods.
The third wrong view is sometimes called either “semi-Arianism” or “homoiousianism”. Don’t worry too much about the names. In that view, like tritheism, Jesus and the Father are different gods. But the difference from tritheism is that Jesus and the Father are the same kind of thing. They have the same general nature. So, a bit like you and I are both human beings, but we are different human beings.
But the orthodox view of Jesus is that he and the Father are not simply both types of a thing called “God”. They are actually the same essence or being.
Finally, there is modalism. Modalism is the view I mentioned before, where Jesus simply is the Father, but another kind of mask that God can put on from time to time.
But the orthodox view is that Jesus is not the Father, nor is he the Spirit. And yet together, Father, Son and Spirit are the one God.
Those convictions were crystallised in the 4th century in something known as the Nicene creed.
It says,
I believe in one God, the Father Almighty, Maker of heaven and earth, and of all things visible and invisible.
And in one Lord Jesus Christ, the only-begotten Son of God, begotten of the Father before all worlds; God [from] God, Light [from] Light, very God [from] very God; begotten, not made, being of one substance with the Father, by whom all things were made.
…
And I believe in the Holy Ghost, the Lord and Giver of Life; who proceeds from the Father and the Son; who with the Father and the Son together is worshipped and glorified; who spoke by the prophets.
There is one God, one Lord, one Holy Spirit. And the Lord Jesus is “God of God”, “very God of very God”, “being of one substance with the Father”.
Similarly, the Spirit is the “Lord” and, like the Son is from the Father, the Spirit is from the Father and the Son.
One God, one essence and substance, three distinct persons.

Outro

But you might wonder, “how important is all this anyway?”
Well, as the writer Michael Reeves notes,
what makes Christianity absolutely distinct is the identity of our God. Which God we worship: that is the article of faith that stands before all others. The bedrock of our faith is nothing less than God himself, and every aspect of the gospel—creation, revelation, salvation—is only Christian insofar as it is the creation, revelation and salvation of this God, the triune God. I could believe in the death of a man called Jesus, I could believe in his bodily resurrection, I could even believe in a salvation by grace alone; but if I do not believe in this God, then, quite simply, I am not a Christian. And so, because the Christian God is triune, the Trinity is the governing center of all Christian belief, the truth that shapes and beautifies all others. The Trinity is the cockpit of all Christian thinking.
The trinity matters because that’s what the Bible teaches. But as we’ll see in the next episode, it matters too because our salvation depends on the Trinity being the Trinity. If the Son wasn’t God we couldn’t be saved, and if the Spirit wasn’t God, we couldn’t be saved either.
Why is that? And how can we get a better grip on the Trinity? That’s what we’re thinking about in the next episode of Thinking Theology.
Please join me then.