Keller’s Case for Belief in an Age of Skepticism
❧ ✦ ❧
Introduction: “Which One of You Is Lying?”
As a teenager in a Lutheran church in eastern Pennsylvania, Timothy Keller sat through a two-year confirmation class taught by two very different men. The first year’s teacher, a retired minister, spoke of a holy God whose wrath could be turned aside only at great cost. The second year’s teacher, fresh from seminary, spoke of a spirit of love in the universe whose chief demand was that we work for human rights. Keller later wrote that it was almost like being instructed in two different religions, and the question he wanted to ask his instructors was simple: “Which one of you is lying?” At fourteen, he kept quiet.
Decades later, Keller spent his career asking and answering that kind of question out loud. In 1989 he and his wife, Kathy, started Redeemer Presbyterian Church in Manhattan, a city that nearly everyone told him was the wrong place for a church teaching the orthodox, historic tenets of Christianity. By the end of 2007, Keller reports, the church had grown to more than 5,000 attendees, most of them young, single, and drawn from the very population that was supposed to have no use for faith. For years he stayed after Sunday services to field questions from skeptics, critics, and seekers. The Reason for God, first published in 2008, is the distilled record of those conversations.
The book’s premise is announced in its introduction and carried through every chapter: believers should wrestle honestly with doubt, and skeptics should recognize that their doubts rest on beliefs of their own. The first half examines the seven objections to Christianity Keller heard most often. The second half lays out the positive reasons he believes Christianity makes the most sense of the world and of human experience.
❧ ✦ ❧
The Central Idea: Every Doubt Is a Leap of Faith
Keller opens by describing a culture polarized over religion. Skepticism is rising, he notes, but so is robust, orthodox belief, especially across Africa, Latin America, and Asia. Each side tends to denounce rather than reason with the other. His proposal for a way forward is to look at doubt “in a radically new way.”
For believers, he argues that a faith without doubts is like a body without antibodies: it collapses at the first serious challenge. For skeptics, he makes the claim that drives the entire book:
All doubts, however skeptical and cynical they may seem, are really a set of alternate beliefs. You cannot doubt Belief A except from a position of faith in Belief B.
— Timothy Keller, The Reason for God
A person who says “there can’t be just one true religion” is making a claim that cannot be proven empirically and that most of the world does not accept. The fair thing, Keller says, is to identify the belief beneath each doubt and ask for the same evidence for it that one demands of Christianity. “In fairness you must doubt your doubts.” His goal is not victory but a higher quality of disagreement, in which each side can state the other’s view in its strongest form before rejecting it.
❧ ✦ ❧
Part One: The Leap of Doubt
Each chapter in the first half opens with a short exchange between young New Yorkers voicing a common objection, and then examines the assumption hidden inside it.
1. “There Can’t Be Just One True Religion”
Keller agrees that religion can create a “slippery slope in the heart,” in which a sense of having the truth leads to feelings of superiority and, finally, to oppression. But he finds each of the popular remedies wanting. Outlawing religion, as twentieth-century communist regimes attempted, produced more violence rather than less, and the old prediction that religion would fade with modernity has not come true. Condemning exclusive claims runs into self-contradiction: the assertion that all religions are equally valid is itself a doctrine about God that contradicts every major faith. The well-known parable of the blind men and the elephant backfires, Keller observes, because it is told from the point of view of someone who can see the whole elephant.
Keeping religion strictly private fails too, because every moral argument in public life rests on some unprovable view of what human beings are for. Keller concludes:
It is no more narrow to claim that one religion is right than to claim that one way to think about all religions (namely that all are equal) is right. We are all exclusive in our beliefs about religion, but in different ways.
— Timothy Keller, The Reason for God
The real question, then, is which exclusive beliefs lead their holders to love those who differ from them. Keller points to the early church, which held that there was only one true God yet cared for the poor, the sick, and the marginalized of other faiths, and he locates the source of that behavior in a Savior who died for his enemies and prayed for their forgiveness.
2. “How Could a Good God Allow Suffering?”
Keller takes this objection seriously, both as a philosophical argument and as a personal wound. Philosophically, he notes that the argument from evil depends on a hidden premise: if evil appears pointless to me, it must be pointless. Just because we cannot see a reason for suffering does not mean there is none. He illustrates from the story of Joseph in Genesis and from people in his own congregation, including a man who lost his eyesight and said the loss finally opened his “spiritual eyes.”
If you have a God great and transcendent enough to be mad at because he hasn’t stopped evil and suffering in the world, then you have (at the same moment) a God great and transcendent enough to have good reasons for allowing it to continue that you can’t know.
— Timothy Keller, The Reason for God
Following C. S. Lewis, Keller argues that suffering may be a bigger problem for unbelief than for belief: outrage at injustice assumes a standard of justice that a purely natural world cannot supply. Yet he does not stop at argument. Christianity, he says, does not explain each instance of pain, but it offers two resources for facing it. The first is the cross, where God himself entered human suffering and experienced the ultimate abandonment; we may not know why God allows evil, but we know it is not because he is indifferent. The second is the resurrection, which promises not merely consolation for lost lives but the restoration of the life we always wanted. Borrowing from Tolkien’s Sam Gamgee, Keller writes that “everything sad is going to come untrue and it will somehow be greater for having once been broken and lost.”
3. “Christianity Is a Straitjacket”
Many people fear that Christianity’s claim to absolute truth threatens freedom. Keller responds on several fronts. Truth-claims are unavoidable: the argument that all truth-claims are power plays is itself a truth-claim. Every community, however inclusive its reputation, has beliefs that act as boundaries, so the better test of a community is how it treats outsiders. And Christianity, far from being a cultural straitjacket, has taken root in more cultures than any other faith; its center of gravity has moved from Jerusalem to the Mediterranean, to Europe, and now to the global South.
His most memorable argument concerns freedom itself. A fish is free only when it is confined to water; a pianist gains freedom through years of disciplined practice. Freedom is found not in the absence of restrictions but in the right ones.
Freedom, then, is not the absence of limitations and constraints but it is finding the right ones, those that fit our nature and liberate us.
— Timothy Keller, The Reason for God
The most liberating constraint of all, Keller argues, is love, which always requires a mutual loss of independence. What makes Christianity different is that God has first “adjusted” to us, becoming human and dying in our place. Once a person grasps that, obedience feels less like a cage and more like what lovers do for one another.
4. “The Church Is Responsible for So Much Injustice”
Keller does not minimize the failures of Christians. He addresses three: the poor character of many believers, the church’s history of violence, and fanaticism. On character, he explains that Christianity teaches salvation by grace, not moral attainment, so the church will naturally contain many broken people still in progress. As the saying goes, “The church is a hospital for sinners, not a museum for saints.” On violence, he notes that the secular regimes of the twentieth century were at least as violent as religious ones, which points to something deeper in the human heart than any particular creed.
On fanaticism, his diagnosis is pointed. Overbearing, self-righteous Christians are not too committed to the gospel but not committed enough:
They are fanatically zealous and courageous, but they are not fanatically humble, sensitive, loving, empathetic, forgiving, or understanding—as Christ was.
— Timothy Keller, The Reason for God
Keller adds that the Bible contains its own critique of oppressive religion, from Isaiah and Amos to Jesus’s denunciations of the religious establishment. He then surveys Christian self-correction in history: the abolitionists led by William Wilberforce, the Civil Rights movement, Desmond Tutu’s Truth and Reconciliation Commission, the Polish priest Jerzy Popieluszko, Archbishop Oscar Romero, and Dietrich Bonhoeffer. Of Martin Luther King Jr., Keller writes that “the greatest champion of justice in our era knew the antidote to racism was not less Christianity, but a deeper and truer Christianity.”
5. “How Can a Loving God Send People to Hell?”
Keller calls divine judgment one of Christianity’s most offensive doctrines in contemporary culture, and he begins by asking readers to consider their cultural location. Western secular people bristle at judgment but love the call to forgive enemies; people in many traditional cultures feel exactly the reverse. If Christianity is true, he reasons, it would be expected to offend every culture somewhere.
He argues that love and wrath are not opposites: a loving person becomes angry precisely at what destroys the one they love. Drawing on Miroslav Volf, who witnessed the violence in the Balkans, he suggests that belief in a God who will finally set things right is what frees victims to renounce personal vengeance. Hell itself, in Keller’s reading, is not a place where repentant souls beg in vain for release. It is the end of a self-chosen trajectory away from God, the source of all joy and love.
In short, hell is simply one’s freely chosen identity apart from God on a trajectory into infinity.
— Timothy Keller, The Reason for God
He leans heavily on Lewis’s The Great Divorce, in which visitors from hell refuse to leave their self-absorption behind even when invited into heaven:
There are only two kinds of people—those who say “Thy will be done” to God or those to whom God in the end says, “Thy will be done.”
— C. S. Lewis, as quoted in The Reason for God
Finally, Keller recounts how his own study of world religions in college undermined his belief in a God of pure, nonjudging love. He found no other religious text that taught that God created the world out of love and delight. The idea that God is love, he concludes, comes from the Bible itself, and the same Bible presents that loving God as a judge who will put the world right.
6. “Science Has Disproved Christianity”
Keller distinguishes between science as a method and philosophical naturalism as a worldview. Science, by design, tests for natural causes; it cannot prove that no other kind of cause exists. To be certain that miracles cannot happen, one would have to be certain there is no God, which is itself an article of faith.
He disputes the popular “warfare” model of science and religion, citing surveys of scientists’ beliefs, the example of Human Genome Project head Francis Collins, and atheist thinkers such as Stephen Jay Gould and Thomas Nagel who reject the claim that science and faith must be at odds. On evolution, Keller distinguishes between evolution as a biological process, which many Christians accept, and evolution as an “All-encompassing Theory” that explains everything we believe and feel. He sets out the range of positions Christians hold and states his own: that God guided some process of natural selection, and that Genesis 1 reads like a “song” about creation, alongside Genesis 2 as the account of what happened. He urges seekers not to let this intramural debate distract them from the central question of who Jesus was. Miracles, he adds, were never magic tricks in the gospels but signs of restoration:
Jesus’s miracles are not just a challenge to our minds, but a promise to our hearts, that the world we all want is coming.
— Timothy Keller, The Reason for God
7. “You Can’t Take the Bible Literally”
This chapter addresses two complaints: that the Bible is historically unreliable and that it is culturally regressive. On history, Keller offers three reasons for trusting the gospels. First, the timing is too early for legend. The gospels were written within the lifetimes of eyewitnesses, and Paul’s letters, even earlier, appeal to hundreds of living witnesses. Drawing on Richard Bauckham’s Jesus and the Eyewitnesses, Keller notes how gospel writers named sources readers could consult. Second, the content is too counterproductive to be invented: women as the first witnesses to the resurrection, Jesus pleading in Gethsemane, and the apostles portrayed as slow and cowardly. Third, the gospels contain incidental details, such as the cushion in the boat and the 153 fish, which Lewis noted are unlike anything in ancient legend. Keller also contrasts the canonical gospels with the much later Gnostic texts and rejects the historical claims popularized by The Da Vinci Code.
On culture, Keller gives three pieces of practical advice to readers troubled by a passage. Consider that it may not mean what it first appears to mean (first-century bond-service, he explains, differed sharply from New World chattel slavery). Consider that labeling a text “regressive” assumes our own historical moment is the final standard. And distinguish the Bible’s core teachings from its secondary ones; settle the question of the resurrection before worrying over disputed texts. He ends the chapter with one of the book’s most quoted images, the “Stepford God,” a deity edited until he can never contradict us:
So an authoritative Bible is not the enemy of a personal relationship with God. It is the precondition for it.
— Timothy Keller, The Reason for God
❧ ✦ ❧
Intermission: Which Christianity? Which Rationality?
Between the two halves of the book, Keller pauses to define his terms. By “Christianity” he means the shared faith of the great ecumenical creeds held by Orthodox, Catholic, and Protestant believers alike, while acknowledging that he writes as a Protestant when he describes sin and grace.
By “sufficient reasons,” he does not mean airtight proof. He rejects what he calls “strong rationalism,” the demand for an argument no rational person could refuse, noting that this standard cannot meet its own test and that even atheist philosophers like Thomas Nagel admit they cannot approach the question of God without strong motives. Keller adopts instead “critical rationality”: weighing which account of the world best explains what we observe, the way scientists weigh theories. He then borrows an image from C. S. Lewis, who responded to a cosmonaut’s report of not finding God in space by comparing it to Hamlet searching the attic for Shakespeare.
If the God of the Bible exists, he is not a man in the attic, but the Playwright.
— Timothy Keller, The Reason for God
We can know the Playwright only as far as he reveals himself in the play, and Christians believe he did more than leave clues: he wrote himself into the story as its main character.
❧ ✦ ❧
Part Two: The Reasons for Faith
8. The Clues of God
Keller presents his arguments for God not as proofs but as “clues” whose combined weight is considerable. He reviews the origin of the universe in the Big Bang, the fine-tuning of physical constants that make life possible, the regularity of nature on which all science depends, and the longing awakened by beauty, which, following Augustine and Lewis, he treats as an innate desire pointing to something real. Each clue, he concedes, can be rationally avoided. Philosopher Alvin Plantinga’s poker player who deals himself twenty straight hands of four aces illustrates the point: you cannot prove he cheated, but it would be unreasonable to conclude he did not.
Keller then takes on the “clue-killer,” the evolutionary argument that religious belief exists only because it once helped our ancestors survive. If our minds were shaped only for survival rather than truth, he argues, the same suspicion would apply to every belief, including belief in evolutionary theory. The clue-killer, he concludes, becomes one more clue.
The theory that there is a God who made the world accounts for the evidence we see better than the theory that there is no God.
— Timothy Keller, The Reason for God
9. The Knowledge of God
Here Keller makes a bolder claim: that people already know God exists, even if they deny it. The young secular New Yorkers he meets are not amoral; they hold strong moral convictions about human rights and injustice. But when pressed, they cannot say where those convictions come from. Keller surveys secular attempts to ground human rights, from Alan Dershowitz and Ronald Dworkin to Michael Perry, and highlights Yale law professor Arthur Leff’s “grand Sez Who?”: without God, who has the authority to declare any moral law binding? Leff nonetheless ended his essay insisting that some things, such as napalming babies, are simply evil. Annie Dillard’s observation that nature runs on violence sharpens the point: if violence is natural, our conviction that it is wrong must come from somewhere beyond nature.
If a premise (“There is no God”) leads to a conclusion you know isn’t true (“Napalming babies is culturally relative”) then why not change the premise?
— Timothy Keller, The Reason for God
10. The Problem of Sin
Keller argues that the Christian doctrine of sin, far from being bleak, is a source of hope, because it means we are not simply helpless victims of our drives or circumstances. Drawing on Kierkegaard’s definition of sin as building one’s identity on anything other than God, he redefines sin in terms many modern readers recognize:
So, according to the Bible, the primary way to define sin is not just the doing of bad things, but the making of good things into ultimate things.
— Timothy Keller, The Reason for God
Everyone, Keller says, builds an identity on something: career, romance, family, achievement, moral performance. Whatever that is becomes a kind of god, and it brings predictable consequences. Personally, it produces anxiety, bitterness, and something like addiction. Socially, as Jonathan Edwards argued, it fractures communities, since whoever makes their family, race, or cause the ultimate will look down on those outside it. Cosmically, the Bible describes the loss of shalom, the full flourishing of creation. The answer is not trying harder but reorienting the whole life around God.
Jesus is the only Lord who, if you receive him, will fulfill you completely, and, if you fail him, will forgive you eternally.
— Timothy Keller, The Reason for God
11. Religion and the Gospel
This chapter contains what many readers regard as the heart of the book. Keller uses “religion” to mean salvation through moral effort and “gospel” to mean salvation through grace. He illustrates with Stevenson’s Dr. Jekyll and Mr. Hyde: Jekyll tries to suppress his evil self with good works, only to turn into Hyde at the moment of his proudest self-congratulation. There are two ways to be one’s own savior, Keller says: by breaking all the rules, or by keeping them in order to put God in one’s debt.
Religion operates on the principle “I obey—therefore I am accepted by God.” But the operating principle of the gospel is “I am accepted by God through what Christ has done—therefore I obey.”
— Timothy Keller, The Reason for God
The difference shows up in motivation (fear versus gratitude), in self-image (swinging between pride and self-loathing versus a humble confidence), in how one treats outsiders, and in how one handles suffering. Keller adds that grace is not a license, using a woman’s comment that if she were saved by sheer grace, there would be nothing God could not ask of her. Victor Hugo’s Les Misérables supplies the contrast: Jean Valjean is transformed by the bishop’s mercy, while Javert, unable to accept grace, destroys himself.
12. The (True) Story of the Cross
Why did Jesus have to die? Why can’t God simply forgive? Keller answers that real forgiveness is always costly. When someone wrongs us, the debt does not disappear; either we make the wrongdoer pay, or we absorb the cost ourselves. Forgiveness feels like a kind of death, but it leads to resurrection rather than the living death of bitterness. Bonhoeffer serves as the human example. On the cross, Keller argues, God did on a cosmic scale what every forgiver must do, and because Jesus is God, God was not inflicting pain on someone else but absorbing it himself.
A second reason is that life-changing love always involves exchange, a reversal of places, as any parent or counselor knows. Keller calls the cross the “Great Reversal”: God, from the place of ultimate power, takes his place among the powerless. He closes with stories of substitution, Angels with Dirty Faces and A Tale of Two Cities, and explains that such stories once moved him without changing him. The gospel did change him because it is a true story he is actually in.
The fact that Jesus had to die for me humbled me out of my pride. The fact that Jesus was glad to die for me assured me out of my fear.
— Timothy Keller, The Reason for God
13. The Reality of the Resurrection
Keller treats the resurrection as the hinge of the whole case:
If Jesus rose from the dead, then you have to accept all he said; if he didn’t rise from the dead, then why worry about any of what he said?
— Timothy Keller, The Reason for God
Drawing primarily on N. T. Wright’s The Resurrection of the Son of God, he argues that the skeptic carries a burden of proof as well: an alternative explanation for the birth of the church. The earliest testimony, in 1 Corinthians 15, predates the gospels and names witnesses who were still alive. The empty tomb and the appearances must be taken together, since either alone would not have produced belief in resurrection. Keller also challenges what Lewis called “chronological snobbery”: neither Greeks nor Jews of the first century would have found an individual bodily resurrection believable. Other messianic movements ended when their leaders were executed; this one exploded, and its Jewish followers began worshipping Jesus almost immediately. Even skeptics who cannot believe, Keller says, should want the resurrection to be true, since it gives ultimate meaning to the work of justice and healing they care about.
14. The Dance of God
The final chapter draws the threads together into the Bible’s four-act drama: creation, fall, redemption, and restoration. At its center is the doctrine of the Trinity, which Keller presents as the key to understanding reality. The Father, Son, and Spirit have eternally glorified and delighted in one another, a mutual self-giving that the early Greek church called perichoresis, a word related to dance. Because God is a community of love, love is not a late arrival in the universe but its foundation.
Ultimate reality is a community of persons who know and love one another.
— Timothy Keller, The Reason for God
God created, Keller argues, following Jonathan Edwards, not out of need but to share his joy. Humanity lost the dance by becoming self-centered, demanding that everything orbit around itself. In Jesus, the “last Adam,” God moved toward us, and he invites us back into the dance. The story ends not with escape from the material world but with heaven descending to renew it. The Christian life, then, includes worship, evangelism, community, justice for the poor, and care for creation, all lived in anticipation of a restored world.
❧ ✦ ❧
Epilogue: Where Do We Go from Here?
Keller closes with practical counsel for readers who find themselves drawn toward faith. He asks them to examine their motives: are they seeking to serve God, or to get God to serve them? He presses the all-or-nothing nature of Jesus’s claims, citing Bono and Flannery O’Connor’s Misfit. For those still hesitant, he offers an inventory of content, coherence, and cost questions to work through in community.
Becoming a Christian, he explains, takes “two things, and a third.” The first is repentance, not only for wrong deeds but for the “self-salvation project” beneath both our bad and good works. The second is faith, which he defines as trust and illustrates with a falling climber grabbing a branch:
Strong faith in a weak branch is fatally inferior to weak faith in a strong branch.
— Timothy Keller, The Reason for God
The third is joining a church, which Keller compares to the ocean: vast and varied, with both safe waters and dangerous currents, but impossible to do without. He ends with Flannery O’Connor’s short story “Revelation,” in which the self-satisfied Mrs. Turpin receives a vision of “freaks and lunatics” entering heaven ahead of the respectable, and with a woman from his congregation who changed her prayer from “God, help me find you” to “God, come and find me.”
❧ ✦ ❧
Conclusion: A Watertight Person
The Reason for God is not a book of knockout arguments, and Keller says plainly that it does not try to be one. Its method is to turn the lens around: to show skeptics the faith hidden in their doubts, to show believers the doubts they need to face, and to argue that Christianity offers the most coherent account of a world that feels both beautiful and broken, and of human beings who are, in his phrase, “very flawed and yet very great.”
In the 2018 preface, written a decade after the book first appeared, Keller writes that he hoped to make his case with “both respect for skeptics and yet the confidence that Christian faith is cogent.” In the epilogue, he recounts a pastor’s reply to a man who wanted a watertight argument before he would believe: “What if God hasn’t given us a watertight argument, but rather a watertight person?” That question captures the book’s final move. After fourteen chapters of reasoning, Keller sets argument aside and points to Jesus himself: his claims, his cross, and his resurrection. Whatever a reader concludes, the book leaves them with a question Keller believed every honest person must eventually answer: if every doubt rests on a belief, which belief is strong enough to bear the weight of a life?
❧ ✦ ❧
Citations
Keller, Timothy. The Reason for God: Belief in an Age of Skepticism (PDF). New York: Penguin Books, 2018. Edition with a new preface; originally published by Dutton, 2008. Available on Amazon.
Quotations attributed to C. S. Lewis, Arthur Leff, and others are cited as they appear in Keller’s text. Lewis’s line on “two kinds of people” is from The Great Divorce.