The Christian church spans widely. Catholics, Greek Orthodox, and Protestants, with thousands of denominations within Protestantism alone. Think of it like national and provincial boundary lines. We're in Alberta. Go west, and you're in a different province but still in the same country. Go south, and you're in a whole new country.
You can cross some provincial boundaries and remain within the historic Christian faith. Things like church governance or the understanding of sacraments are important, but Christians can land in different places. National boundary lines, though, you cannot cross. If you do, you are not in Christianity anymore.
The doctrine of the Trinity is one of those national boundary lines. And it answers the most fundamental question: Who is God?
Here's the definition:
God eternally exists as three persons, Father, Son, and Holy Spirit, and each person is fully God, and there is one God.
You don't need to be a genius to see the problem. It's this non-negotiable Christian claim that the world scoffs at. Muslims use it as evidence that Christianity is incoherent. Jews use it to argue that Christians are polytheists. The rest of the world concludes that Christians can't do math.
Christians themselves can be embarrassed by the Trinity because they can't comprehend it, let alone explain it.
But the doctrine of the Trinity is not Christianity's embarrassment. It is our crown jewel.
God's Character vs. God's Nature
When we talk about who God is, we're really talking about two things: God's character and God's nature.
God's character is His love, justice, mercy, and kindness. Theologians call these God's communicable attributes, meaning they can be shared with humans. Because you have love, you can be merciful. You can be kind. Although God is perfect in these attributes, we can understand them because we have them in part.
God's nature is much harder. These are incommunicable attributes, things that cannot be shared with humans. They are God's and God's alone.
Here's a simple question that exposes the problem: What is your nature?
You're supposed to know yourself better than anyone, and yet if I asked you to explain your own nature, you'd likely struggle. We barely know how to think about ourselves. And now we're going to wrap our minds around the nature of God?
We have a gender; God does not. We have parents; God does not. We had a beginning; God did not. We were created; God was not. He is categorically other.
The only way we can know God's nature is by what He reveals about Himself. As Jesus said, "No one knows the Father except the Son and anyone to whom the Son chooses to reveal him" (Matthew 11:27). Paul adds, "No one knows the thoughts of God except the Spirit of God" (1 Corinthians 2:11).
We cannot know God exhaustively, but we can know Him accurately. And from cover to cover, what we see is this: God eternally exists in three persons, Father, Son, and Holy Spirit. Each one is God. And there is only one God.
Augustine on the Beach
There's a story about St. Augustine, a 4th-century church father who wrote extensively on the Trinity. The story is likely just that, a story, but it's helpful nonetheless.
Augustine was walking along the seashore, deeply thinking about how God can be Father, Son, and Holy Spirit, yet one God. He was trying to grasp it intellectually.
He noticed a small boy running back and forth from the ocean to a little hole in the sand, scooping water with a shell and pouring it into the hole. Augustine asked the boy what he was doing. The boy replied that he was trying to put the whole ocean into the hole.
Augustine told him it was impossible. The ocean is far too vast and the hole far too small.
The boy answered: "And yet you are trying to fit God into your mind."
The Trinity is a mystery. And that's a feature of the Christian faith, not a bug. As Proverbs 25:2 says, "It is the glory of God to conceal a matter; to search out a matter is the glory of kings."
The honour and joy of our lifetime is to seek out and discover the God who is Father, Son, and Holy Spirit. There's always more. He is an ocean with no bottom. So grab your shell and scoop as much as you can, because that's what we'll be doing for eternity, and still never know Him exhaustively. Yet we can know Him accurately.
What the Bible Reveals
Old Testament: Partial Revelation
In the Old Testament, we have what's called partial revelation. You see traces of the Trinity, but they're dim.
The opening verse sets the stage: "In the beginning God created the heavens and the earth" (Genesis 1:1). The Hebrew word for "God" here is Elohim, a plural noun. You could argue it ought to be translated "In the beginning the gods." But the verb "created" is singular. There's tension in the very first sentence of the Bible, hinting at a plurality of some sort, yet the author clearly has in mind one act and one Creator.
We read passages like:
- "Let us make mankind in our image, in our likeness" (Genesis 1:26)
- "The man has now become like one of us" (Genesis 3:22)
- "Whom shall I send? And who will go for us?" (Isaiah 6:8)
The most common counter-explanation is that these are "plurals of majesty," like a king saying "we are pleased to grant your request." The problem with that idea is that it's off by about 1,000 years. There's no historical record, Hebrew or otherwise, of any plural of majesty until 1,000 years after we see it in Genesis.
In the Old Testament, the clues are there, but they're dim.
New Testament: Full Revelation
When the New Testament arrives, we go from dim to a blazing fire.
Even before Jesus is born, the angel tells Mary: "The Holy Spirit will come on you, and the power of the Most High will overshadow you. So the holy one to be born will be called the Son of God" (Luke 1:35).
At Jesus' baptism, "He saw the Spirit of God descending like a dove and alighting on him. And a voice from heaven said, 'This is my Son, whom I love; with him I am well pleased'" (Matthew 3:16-17). The Son in the water. The Spirit descending. The Father speaking. All three. Simultaneously.
At the end of His earthly ministry, Jesus' final instructions to His followers: "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).
Some find all this three-in-one language too cumbersome. Their solution is to forget the metaphysics and just focus on Jesus. His words. His life. His example.
Honestly? That's good advice. If you walked into my office overwhelmed by your marriage or your family or anxiety, I'm not going to walk you through the historical development of the doctrine of the Trinity. I'm going to point you to Jesus. I'm going to encourage you to trust Him and obey His words.
But here's the irony. When you focus on Jesus and what He says, you end up at the doctrine of the Trinity:
- "I and the Father are one" (John 10:30)
- "Anyone who has seen me has seen the Father" (John 14:9)
- "I will ask the Father, and he will give you another advocate to help you and be with you forever, the Spirit of truth" (John 14:16-17)
To "just focus on Jesus" is great advice, but He is the one who leads you to the feet of the Trinity.
Why Every Analogy Fails
The earliest Christians were left with Scripture declaring one God, hints of plurality throughout, and Jesus claiming to be God and receiving worship, which in the Jewish world was reserved for God alone. This pressure produced the great creeds of the church.
The creeds don't explain the Trinity. They state it.
Every attempt to explain the Trinity with a creaturely analogy fails because it commits a categorical error: assuming you can explain what is uncreated by something that is created.
The three-leaf clover. Three leaves, one clover. Sounds good, right? The problem is that if you pull off a leaf, you have a leaf, not a clover. Each leaf is only one-third of the whole. But each person of the Trinity isn't one-third of God. The Father is fully God. The Son is fully God. The Spirit is fully God.
The water illustration. Water can exist as solid, liquid, or vapour, so God can exist in three persons. The problem is that the same water molecule doesn't exist in all three states simultaneously. The Father, Son, and Holy Spirit don't take turns being God. They eternally exist simultaneously.
The sun analogy. You have the sun, its rays, and its warmth. The Father is the sun, Jesus is the rays, and the Holy Spirit is its warmth. This commits the greatest offence. The rays and warmth are derivatives of the sun, not the sun itself. Apply that to God, and you've just said Jesus and the Holy Spirit are products of the Father, dependent on Him, lesser than Him. Jesus would be a creation, not fully God.
Every creaturely analogy fails. No created thing can contain the uncreated God. He simply exceeds all our categories.
A God you could fully explain in a children's illustration wouldn't be worth the ocean of worship He deserves.
The Nicene Creed and One Iota
The most important creed is the Nicene Creed (325 AD), forged under crisis. A church leader named Arius was teaching that Jesus was exalted, divine even, but ultimately created. Not eternal. Not co-equal with the Father. His famous line: "There was a time when the Son was not."
Easier to square with our minds. Not easy to square with the Bible: "In the beginning was the Word, and the Word was with God, and the Word was God" (John 1:1).
Arius' teaching was spreading fast and splitting the church. Constantine, the Emperor of Rome, called roughly 300 church leaders to modern-day Turkey to settle the question: Who is Jesus, exactly?
A portion of their answer:
We believe in one God, the Father almighty, maker of heaven and earth, of all things visible and invisible.
And in one Lord Jesus Christ, the only Son of God, begotten from the Father before all ages, God from God, Light from Light, true God from true God, begotten, not made; of the same essence as the Father.
Begotten. We don't use that word much. You beget something of the same nature as yourself, not lesser. A human begets a human. A human doesn't beget something less than human. Gophers beget gophers. So what does God beget? God begets exactly God.
Same essence. This was the make-or-break idea of the creed. Arius wanted to say that Jesus was of similar substance with the Father. The word he promoted was homoiousios (homoio = similar, ousios = essence).
This is precisely how Mormons and Jehovah's Witnesses ultimately think of Jesus. They elevate Him, but not to His rightful place, and so they cross a national boundary line and cannot be placed within the historic Christian faith.
Athanasius, the hero of Nicea, saw the consequences of homoi. If Jesus were of similar substance and not the same substance, three things would follow:
- The atonement would be insufficient. The gap between a holy God and sinful humanity is infinite, and only God Himself could bridge it. As a creature, Jesus would need saving Himself.
- Worship of Jesus would be idolatry, because worship is reserved for God alone.
- Jesus claimed to be God. If He isn't, He's a liar. A lying, idolatry-promoting, non-divine Jesus saves no one.
The solution? Remove one letter. One iota. Athanasius fought for homoousios, "same substance."
You've heard the phrase "it doesn't make one iota of difference." Some argue it comes from this exact moment in history, which is funny because one iota made all the difference in the world.
Why It Matters
So who cares? How does this affect Monday morning? Your career? Your family?
A few weeks ago, I was leaving the house in the morning with a lot on my mind. Work challenges. Bills that all seemed to land at once. Family stuff that was eating away at Kim and me. It was just one of those mornings when I felt heavy and distracted.
As I was leaving, I said bye to my family, and my 14-year-old daughter yelled out, "Bye, Dad. I LOVE you!"
The way she said it caught me off guard and made me laugh. She'd told me she loved me many times before, and I knew she loved me, but she had never said it quite like that. So I couldn't help but yell it back, "I LOVE you, too!"
And it was strange. Everything I'd been carrying that morning was just gone. I got into my truck, put on music, and worshipped God on my way to work. I thought, "To be loved like that has to be the reason for living."
Where does love like that come from? And why does it cut through everything else?
The Trinity.
The Bible says, "God is love" (1 John 4:8). It doesn't say "God loves," although He does. It says God is love. It's a nature statement.
How can that be? You would never say a person is love itself, only that they can love or that they are loved. Love needs a subject, someone to do the loving. And love needs an object, someone to receive it.
If God eternally exists as love, who did He love? Did He start loving once He started creating? Was there a time God was not love because He had nothing else to love? No, because God doesn't change. That's also part of His nature.
So if God is love, and He always has been, who did God love?
The Father loved the Son and the Spirit. The Son loved the Father and the Spirit. The Spirit loved the Father and the Son.
At the centre of God's mysterious nature is this: He eternally exists as a fellowship of love between Father, Son, and Spirit.
Love really needs three things:
- Someone to love
- Someone to be loved
- The bond itself, the love that flows between them
Take Kim and me. What makes our relationship special isn't just that I'm a person and she's a person. What is special is the bond between us, the love that binds me to her and her to me.
Augustine drew this out. You have the Father, you have the Son, and the Holy Spirit is the bond of love between them. The way the Father eternally loves the Son is through the Holy Spirit, and the way the Son loves the Father is through the Holy Spirit.
And here's where it gets personal:
"God's love has been poured out into our hearts through the Holy Spirit, who has been given to us." (Romans 5:5)
The same Spirit that bonds the Father to the Son and the Son to the Father overflows and is poured into our hearts.
And then what happens?
"The Spirit you received... by him we cry, 'Abba, Father.'" (Romans 8:15)
Abba is an intimate word for "dad." It's the same word Jesus called the Father while praying to Him. When the Spirit is poured into our hearts through faith in Jesus Christ, somehow we are caught up and share in the relationship that has existed between the Father and Son for eternity.
Let me say this as clearly as I can:
"For God so loved the world that he gave his one and only Son" (John 3:16). This is the Father's way of yelling to you and me, "I LOVE you!"
And then, through faith in Jesus, the Holy Spirit is poured into our hearts so that we can yell back, "I LOVE you, too!"
To be loved like that by God Himself. That has to be the reason for it all. That's why it cuts through everything else.
The Invitation
The Trinity is not primarily a doctrine to be understood. It's a relationship we are welcomed into.
It tells us of a God so far beyond our capacity to explain, yet within our capacity to love and be loved.
The Father, Son, and Holy Spirit have existed from all eternity in a relationship of perfect love. And that relationship has been thrown open to you because of Jesus Christ. God from God, Light from Light, true God from true God, begotten, not made.
"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)
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