“Who do you say that I am?”
This is the question Jesus asked His disciples two thousand years ago. Peter answered with the clarity only grace can give: “You are the Christ, the Son of the living God.” But every generation must answer that same question again. And in our age—one marked by anxiety, despair, and a deep confusion about identity—the stakes feel even higher.
A few years back, in the middle of studying for my psychology licensure exam, my mind wandered (as minds under duress tend to do) and landed on a copy of C.S. Lewis’s Mere Christianity. I flipped to Lewis’s famous “Liar Lunatic Lord argument” about the identity of Christ—one of the most compelling apologetic arguments of the 20th century, and still astonishingly relevant today.
Here’s Lewis in his own words:
I am trying here to prevent anyone saying the really foolish thing that people often say about Him: “I’m ready to accept Jesus as a great moral teacher, but I don’t accept His claim to be God.”…A man who was merely a man and said the sort of things Jesus said would not be a great moral teacher. …He would either be a lunatic—on a level with the man who says he is a poached egg—or else he would be the Devil of Hell.
You can shut Him up for a fool, you can spit at Him and kill Him as a demon; or you can fall at His feet and call Him Lord and God. But let us not come with any patronising nonsense about His being a great human teacher. He has not left that open to us. He did not intend to.
Lewis’s point is disarmingly simple: If Jesus claimed to be God—and He certainly did—then the options are limited. He was either:
- A liar,
- A lunatic,
- Or exactly who He said He was: the Lord.
As Sherlock Holmes famously put it, “When you have eliminated the impossible, whatever remains, however improbable, must be the truth” (from The Sign of Four).
While Holmes may be a fictional detective, his line captures the real logic behind Lewis’s argument: if Jesus was neither insane nor deceptive, we are left with one astonishing (but reasonable) conclusion.
And so, with my Diagnostic and Statistical Manual of Mental Disorders (DSM-5) open on one side of my desk and my Bible on the other, I began an odd but surprisingly fruitful mental exercise: What would a psychologist—using the diagnostic categories of modern clinical science—say about Jesus of Nazareth?
Let’s explore.
Was Jesus a Lunatic? A Clinical Look at the Liar Lunatic Lord Argument
People sometimes assume Lewis exaggerated the “lunatic” option for rhetorical effect. But it’s a real question. If anyone today claimed to be the eternal Son of God, able to forgive sins, existing before Abraham, and capable of raising the dead—well, a mental health professional might reasonably have concerns.
So, let’s examine the evidence.
1. No signs of developmental disorders
If Jesus suffered from profound cognitive impairment, we would expect:
– childhood abnormalities
– difficulty functioning independently
– inability to engage with religious and academic leaders
Yet the Gospels depict a different picture entirely: “…all who heard Him were astounded at His understanding and His answers” (Lk. 2:47). He debated rabbis, read Scripture publicly, and showed advanced reasoning and verbal ability. Nothing in the historical record—Christian, Jewish, or pagan—suggests developmental disability.
2. No symptoms of mania or bipolar disorder
Bipolar mania involves:
– decreased need for sleep
– pressured or disorganized speech
– impulsive, high-risk behaviors
– grandiosity
But Jesus slept (soundly enough to snooze through a storm), spoke with clarity and coherence, and lived with remarkable intentionality. His “grand claims” were paired with extraordinary humility: washing feet, dining with sinners, refusing political power, and willingly accepting torture and death.
That is not bipolar grandiosity. That is something else entirely.
3. No signs of schizophrenia
Schizophrenia typically manifests in early adulthood and includes hallucinations, delusions, disorganized thinking, and negative symptoms like emotional blunting.
We see none of that.
Jesus displayed:
– Consistent emotional depth
– Stable relationships
– Clear thinking
– Insight into others’ motives
– Immense compassion
– A coherent, sustained mission across years
If He were psychotic, the crowds would have dismissed Him—not followed Him in multitudes.
4. No delusional disorder
Delusions are fixed, false beliefs. But a delusional person:
– insists others accept the delusion
– becomes defensive or angry when challenged
– lacks insight when rejected
Jesus does the opposite. He often tells people not to disclose His identity. He responds to hostility without rage. He shows sadness—not surprise—when rejected. And His claims align with His actions: miracles, authoritative teaching, healing, and unprecedented moral clarity.
In short: The clinical evidence points decisively against mental illness.
This was not a man trapped in madness. If anything, He appears more psychologically integrated, resilient, wise, and emotionally balanced than any figure in recorded history.
Which brings us to Lewis’s second option.
Was Jesus a Liar? The Problem of Motive
People lie for various reasons. In psychology we call these secondary gains—what someone gets out of deception. So what, exactly, would Jesus stand to gain?
Money? He had none. He lived off the generosity of others and warned against storing up earthly treasure.
Power? He refused kingship, rejected political rebellion, fled from mobs who wanted to crown Him, and told Pilate: “My kingdom is not of this world” (Jn. 18:36).
Comfort? He had no home, no wealth, and spent years walking dusty roads to heal others.
Fame? His public ministry ends not in glory but in abandonment, torture, and death between criminals.
Liars seek advantage. But Jesus gained no earthly advantage—not one.
If the Gospels describe anything accurately, it is this: Being Jesus of Nazareth was the least strategic way imaginable to improve one’s life. Even His disciples gained nothing but martyrdom (with John exiled). Men don’t die for what they know to be a lie.
The “liar” hypothesis collapses under its own weight.
If Not a Lunatic and Not a Liar…Then Who?
This is where Lewis presses the point home. If Jesus wasn’t crazy and wasn’t lying, then we are confronted with the only option left: He was telling the truth.
And this is where the argument moves from reason to revelation, from psychology to theology, and—importantly—from abstraction to invitation. Because if Jesus is Lord, His identity forces a deep question about our own.
Reason Takes Us Far—But Not All the Way
Pilate’s question still echoes today: “What is truth?” Many never hear the answer because they’re looking at Truth incarnate without recognizing Him.
Socrates glimpsed this unknowingly, reasoning his way to a single, uncreated God whom he revered even when Athens condemned him. The Stoics saw hints of this truth as well, sensing a divine spark in every human person. And St. Paul, preaching in Athens, pointed to their altar “to the Unknown God” and revealed what philosophy alone could not: The Unknown God has become known. The Word became flesh.
Faith does not contradict reason—it completes it. As Aquinas said, “Grace does not destroy nature, but perfects it.” Reason brings us to the edge of a great chasm. Faith helps us cross.
Everyone makes a leap—either to believe or not to believe. Even the most hardened materialist takes a leap of faith when he insists the universe is an accident with no purpose. The real question is not whether we believe. It is who we believe.
The Only Sane Response in an Insane World
So we return to the question: Who do you say that I am?
If Jesus is not a lunatic—which the clinical evidence shows…
If He is not a liar—and His life gives no motive for deception…
Then the only remaining option is the one that shakes the world: He is the Lord.
And if He is the Lord, then the most rational, sane, grounded thing a human being can do is what Thomas did after the Resurrection: to fall on his knees, trembling with awe, and say, “My Lord and my God.”
In a world that feels increasingly chaotic, fragmented, and confused, this confession is not naïve.
It is not escapist.
It is not irrational.
It is, perhaps, the only thing that still makes sense.
Image from Wikimedia Commons
