The Three-Personal God

Today's Scripture

Watch how naturally the one God shows up as three at Jesus's baptism — Son in the water, Spirit descending, Father speaking.

Matthew 3:16-17 — "And when Jesus was baptized, immediately he went up from the water, and behold, the heavens were opened to him, and he saw the Spirit of God descending like a dove and coming to rest on him; and behold, a voice from heaven said, 'This is my beloved Son, with whom I am well pleased.'"

1 John 4:8 — "Anyone who does not love does not know God, because God is love."

The Big Idea

Christians believe in one God who exists as three Persons — Father, Son, and Holy Spirit. Lewis says we should expect God to be stranger than we could invent, the way a cube is stranger than a square. And the payoff is not a math puzzle: it means love is not something God started doing when he made us. Love is what God is, and has always been.

Reflection

A bigger dimension, not a broken equation

Be honest: the Trinity sounds like a contradiction. One God. Three Persons. Doesn't 1 + 1 + 1 = 3?

Lewis's answer is one of the most helpful pictures anyone has drawn. Imagine a world of flat creatures who know only two dimensions. Tell them about a cube, and they will object: "A thing can't be six squares and one shape at the same time!" In their flat world, they would be right. One dimension up, both things are true at once:

"In God's dimension, so to speak, you find a being who is three Persons while remaining one Being, just as a cube is six squares while remaining one cube." — C.S. Lewis, Mere Christianity

The Trinity is not bad arithmetic. It is a report from a dimension above ours. The Bible never sits down and diagrams it; instead it keeps showing us the three Persons in action and insisting there is one God. "In the beginning was the Word, and the Word was with God, and the Word was God" (John 1:1) — with God and was God, in the same breath. Even on the Bible's first page there is a hint of company in the Godhead: "Then God said, 'Let us make man in our image'" (Genesis 1:26). And Jesus sends his friends out "baptizing them in the name" — one name, singular — "of the Father and of the Son and of the Holy Spirit" (Matthew 28:19).

Gregory of Nazianzus, a fourth-century pastor who helped the church find words for all this, described what it feels like to think about:

"No sooner do I conceive of the One than I am illumined by the splendor of the Three; no sooner do I distinguish them than I am carried back to the One." — Gregory of Nazianzus, Oration 40

Your mind bounces between the One and the Three and cannot hold both still. Augustine said that is exactly what we should expect:

"If you comprehend it, it is not God." — Augustine, Sermon 117

A God small enough to fit inside your head would not be big enough to have made your head.

Too strange to be made up

Here Lewis turns the difficulty into evidence. If people were inventing a religion, would they invent this?

"If Christianity was something we were making up, of course we could make it easier. But it is not. We cannot compete, in simplicity, with people who are inventing religions. How could we? We are dealing with Fact. Of course anyone can be simple if he has no facts to bother about." — C.S. Lewis, Mere Christianity

Reality has this signature. Light behaves like a wave and a particle; nobody would have invented that, we were forced into it by facts. The Trinity has the same forced-by-the-facts shape. The first Christians were Jews who recited every morning, "The Lord our God, the Lord is one." They did not want a complicated doctrine. But they had met Jesus, watched him do what only God does, seen him die and rise — and then received the Spirit. The Trinity is not speculation; it is what honest witnesses were cornered into by what actually happened, like the scene at the Jordan in Matthew 3:16-17: Son, Spirit, Father, all present, all distinct, all God.

Jesus himself talks this way constantly. "When the Spirit of truth comes, he will guide you into all the truth... He will glorify me, for he will take what is mine and declare it to you. All that the Father has is mine" (John 16:13-15). Father, Son, and Spirit, handing glory to one another like a family passing dishes around a table.

Begotten, not made

The old creeds insist on a strange-sounding phrase about Jesus: begotten, not made. Lewis spends a whole chapter on those three words, because everything hangs on them. What is the difference?

"What God begets is God; just as what man begets is man. What God creates is not God; just as what man makes is not man." — C.S. Lewis, Mere Christianity

A carpenter makes a birdhouse — and the birdhouse, however lovely, is a different kind of thing from the carpenter. But a father begets a son — and the son is the very same kind of being as the father. Human from human. Life from life.

So when the creed says the Son is "begotten, not made," it is drawing the brightest possible line. Jesus is not the first and best thing God ever constructed — not the top angel, not a junior deity, not a spiritual birdhouse. He is God from God, the same kind of being as the Father, sharing the one divine life eternally. The Bible says it with two images: the Son "is the radiance of the glory of God and the exact imprint of his nature" (Hebrews 1:3) — radiance, the way light pours from a sun that was never without its shining — and "the image of the invisible God, the firstborn of all creation" (Colossians 1:15), the one through whom and for whom everything made was made.

Why does this matter to an ordinary believer on an ordinary Tuesday? Because of what it means for the cross and the manger. If Jesus were merely God's most impressive creature, then at Christmas God sent a representative, and at Calvary God let somebody else absorb the damage. Begotten, not made means God came himself. The love that saves you is not secondhand. And it means that when you look at Jesus — his patience, his fierceness against hypocrisy, his tenderness toward the broken — you are not looking at a portrait of God painted by a gifted artist. You are looking at the exact imprint. The Father is not somewhere behind Jesus, different and colder. What you see is what you get, all the way up.

Why "God is love" needs the Trinity

Now comes the part that turns doctrine into wonder. 1 John 4:8 says "God is love." Not God loves — God is love. But stop and think: love needs someone to love. If God were a single, solitary person, then before creation there was no one for him to love. "God is love" would only have become true after he made us — which would mean God needed us, the way a lonely person needs company.

The Trinity rescues that sentence. Jesus prays, "Father... you loved me before the foundation of the world" (John 17:24). Before there were stars, before there were angels, before there was anything, there was love — Father delighting in Son, Son delighting in Father, in the joy of the Spirit. Tim Keller called this "the dance of God," and he admitted the doctrine is hard precisely because it is so rich:

"The doctrine of the Trinity overloads our mental circuits. Despite its cognitive difficulty, however, this astonishing, dynamic conception of the triune God is bristling with profound, wonderful, life-shaping, world-changing implications." — Tim Keller, The Reason for God

The first implication: you were not made to fill a gap in God. He was not lonely. You were made because the love at the center of reality is the overflowing kind — and salvation means being adopted into that family life. J.I. Packer said this is the very summit of the gospel:

"Adoption is the highest privilege that the gospel offers: higher even than justification." — J.I. Packer, Knowing God

Forgiveness clears the record. Adoption gives you a seat at the table — the table where Father, Son, and Spirit have been delighting in one another forever.

The Trinity in your bedroom tonight

Lewis refuses to leave this in the lecture hall. His favorite proof of the Trinity is not an argument but an experience — what actually happens when an ordinary person prays:

"An ordinary simple Christian kneels down to say his prayers. He is trying to get into touch with God. But if he is a Christian he knows that what is prompting him to pray is also God... God is also the road or bridge along which he is being pushed to that goal... the whole threefold life of the three-personal Being is actually going on in that ordinary little bedroom where an ordinary man is saying his prayers." — C.S. Lewis, Mere Christianity

Did you catch it? When you pray, you pray to the Father, prompted by the Spirit, through the Son who stands beside you as both God and man. You are not shouting across a canyon at a distant deity. You are standing inside a conversation that has been going on forever, and the three Persons are carrying your small voice along. That is why Paul's favorite blessing names all three: "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).

The gospel, it turns out, is not just that God forgives you. It is that the eternal dance of love opened a place in the circle — and the Son went to a cross to bring you into it.

Going Deeper

Tonight, pray one short prayer in deliberate Trinitarian slow motion. Begin: "Holy Spirit, you are the one stirring me to pray." Then: "Lord Jesus, you are beside me, carrying this prayer." Then: "Father, I am coming to you as your child." Pray for one real thing in your life that way. You are not performing a formula — you are noticing, maybe for the first time, the threefold life that Lewis says has been going on in the room every time you ever prayed.