The Trinity is easily one of the hardest concepts to navigate in Christianity. For some, it can even be a barrier to accepting Christianity. If you’ve ever found yourself in that awkward conversational dance when you have to explain how God could be three entities at once, let me share with you the best conceptual explanation of the Trinity I’ve ever read.

It comes from A Severe Mercy, by Sheldon Vanauken. After becoming a Christian (which is an incredible story in itself), Vanauken began regularly hosting friends, colleagues, and students at his Oxford studio to discuss Christianity. A non-Christian friend asked Vanauken how Jesus could be completely God and completely man—a concept which to him (and perhaps, even you) appeared to fly in the face of common sense. He says, “You Christians always take refuge in mysteries.”

How Jesus is fully man and fully God

After another Christian friend fumbled through a description of the “persons of God,” Vanauken made a profound connection. He and his wife, Davy, had just talked about writing a novel—one in which they themselves would be characters.

Do you see where this is going?

“‘Okay, suppose I write it—it’s too complicated with two authors—and I put myself in it,’” Vanauken says. “‘There I am, walking down the High, wearing a Jesus tie—in the book. And let’s say I make up a lot of characters, not using real people for fear of hurting their feelings. But I am in it, and I, the character, say whatever I would say in the various situations that occur in my plot.’”

Right now, you can imagine what you would say or do in situations you’ve never been in. You know yourself well enough to have a pretty good idea how you would act, feel, and think in that moment.

When you write, you are creating a new world. And as the creator of that world, you can enter it. 

God wrote himself into the story.

“‘Don’t you see?’” Vanauken says. “‘I am incarnate in my book. I am out here writing it, so I’m like God the Father. But it’s really me in the book, too, isn’t it? So that’s Jesus, the Son, right? The me in the book speaks my words—and yet they are speeches that I’ve probably never made in real life, not being in those situations. And yet can’t you see that it’s really me?’”

The version of him in the book is independent of the version of him that is writing the book, but it’s still him.

“‘I’m out here, being the “Author of all things” and I’m in the book, taking part in the scenes of the “drammer”. Incarnate in my book. Now, the me in the book: he’s all me, isn’t he? And he’s all character, too, isn’t he? Like the doctrine: All God and All man.’”

Jesus is God in a human body—the creator incarnated in his creation.

Why Jesus had to die

Vanauken even goes on to suggest a reason why, even though God is the author of creation, Jesus had to die in his “story”:

“‘And one more thing: suppose the characters run away with the story—authors are always saying that happens. It might be necessary, whatever I had originally intended, for me to get killed . . .”

A well-developed fictional character can essentially write the story for you. In On Writing, Stephen King explains how when a character has a life of his/her own, the story takes shape around how the character navigates the situations the author puts them in. He says, “I think the best stories always end up being about the people rather than the event, which is to say character-driven.”

God created the world. Then he put us in it. Humanity plus sin drastically changed the story.

Where the Holy Spirit fits in

Vanauken’s wife, equally active in many of these conversations, added the final piece to this brilliant explanation of the Trinity: the Holy Spirit.

“‘If Van invents characters, they’ll all, even the bad ones, have something of Van in them, won’t they? So you see? We all have something of God in us—God’s spirit—but only the One, Jesus, is God Incarnate.”

When you create characters, even characters that are completely unlike yourself, a little piece of you goes into them. Whether it happens consciously or not, the act of creating inevitably leaves the mark of the creator on his or her creation.

If you’ve wrestled with popular metaphors for the Trinity (like the three states of water, or the three major components of an egg), you’re aware that no analogy or metaphor is perfect: this one is no exception. All humans are made in the image of God—that’s his mark—but not all humans contain the Holy Spirit. For that, we have to accept Christ.

Update: as some have pointed out in the comments, the greatest weakness of this analogy is that it would suggest both Jesus and the Spirit originated from God, instead of existing with God from the beginning (John 1:1).

However, I think you’ll see that even the Holy Spirit component of the metaphor can still be helpful. The Spirit is still God, but removed from both God the author and God the character (Jesus). The Spirit influences all of God’s other characters in ways we cannot always identify. Sometimes the Spirit contradicts what we, the well-developed characters, would choose to do of our own accord—the Spirit relays the vision of the author.

God is the author of creation. He wrote himself into the story as Jesus. His Spirit influences his characters (us).