The Work
The Reason for God: Belief in an Age of Skepticism was published in February 2008 by Dutton (New York). It is approximately 310 pages, organized into two parts of seven chapters each, plus an interlude and epilogue. Part 1 ('The Leap of Doubt') addresses seven major objections to Christianity; Part 2 ('The Reasons for Faith') presents seven positive arguments for Christianity's truth. The book debuted at number seven on the New York Times bestseller list and remained on the list for forty-seven weeks. It has sold over a million copies and has been translated into numerous languages. A study guide and video curriculum were developed for small-group use. An expanded edition was published in 2018.
Biblical Engagement
Keller's approach to Scripture throughout the book mirrors Paul's strategy in the Areopagus speech in Acts 17:22-34. Paul does not begin with Scripture - he begins where his Athenian audience is, with their own poets and philosophers ('as certain also of your own poets have said, For we are also his offspring,' Acts 17:28), before moving to the claims of Christ. Keller employs the same strategy: he addresses secular objections on their own terms, using philosophy, literature, and culture as bridges to biblical faith.
Romans 2:14-15 ('For when the Gentiles, which have not the law, do by nature the things contained in the law, these, having not the law, are a law unto themselves: Which shew the work of the law written in their hearts') provides the philosophical foundation for the moral argument. Keller argues that the universal human sense of justice - including the secular skeptic's passionate objection to injustice, suffering, and oppression - cannot be explained on purely naturalistic grounds and points toward the moral lawgiver of Romans 1-2.
John 18:37-38 (Pilate's question, 'What is truth?') introduces the epistemological section: Keller argues that postmodern skepticism about absolute truth is self-defeating - the claim 'there are no absolute truths' is itself presented as an absolute truth - and that the Christian claim to revealed truth (John 14:6, 'I am the way, the truth, and the life') is more epistemologically honest than secular relativism.
Isaiah 55:6-9 ('Seek ye the LORD while he may be found, call ye upon him while he is near... For my thoughts are not your thoughts, neither are your ways my ways, saith the LORD') provides the biblical language of the divine transcendence that underlies Keller's treatment of divine hiddenness - the objection that God, if real, should be more obvious.
The book's argument for the resurrection (Chapter 13) draws on 1 Corinthians 15:3-8 and the Gospel accounts, engaging with N.T. Wright's scholarly work. Keller follows Wright's argument that neither Jewish messianic expectation nor pagan resurrection mythology adequately explains the specific form of the early Christian resurrection proclamation - a bodily resurrection as a historical event within time rather than a spiritual ascent after death.
The chapters on sin and the cross draw on Romans 3:21-26 (the righteousness of God revealed in the cross), Isaiah 53 (the suffering servant), and Mark 10:45 ('the Son of man came not to be ministered unto, but to minister, and to give his life a ransom for many'). Keller's treatment of the atonement draws on both the legal/substitutionary model and the Christus Victor model, arguing that the cross simultaneously bears sin's penalty, defeats sin's power, and demonstrates the ultimate depth of love.
Author & Context
Timothy James Keller was born in 1950 in Allentown, Pennsylvania, and raised in a Lutheran home. He was educated at Bucknell University (BA), Gordon-Conwell Theological Seminary (MDiv), and Westminster Theological Seminary (DMin). He served as a pastor in Hopewell, Virginia, and on the faculty of Westminster Seminary before founding Redeemer Presbyterian Church in Manhattan in 1989 with a handful of people.
Redeemer Presbyterian grew to over five thousand weekly attendees, primarily young professionals, graduate students, and artists in their twenties and thirties - a demographic notoriously resistant to organized religion. The church's unusual success in a highly secular urban context was partly a function of Keller's approach: his preaching engaged seriously with secular objections, drew on literature, film, and philosophy as well as Scripture, and presented Christianity as intellectually credible to highly educated skeptics. The Reason for God was the distillation of twenty years of this engagement.
The cultural context was the early twenty-first century's 'new atheism.' Richard Dawkins's The God Delusion (2006), Sam Harris's The End of Faith (2004), and Christopher Hitchens's God Is Not Great (2007) had all achieved bestseller status and brought atheist arguments into mainstream popular culture. Keller's book was the most intellectually serious evangelical response, engaging these arguments at their strongest rather than dismissing them.
Keller's intellectual formation drew on a remarkably diverse set of sources. Reformed theology - particularly the Westminster Confession and its interpreters (John Frame, Cornelius Van Til) - provided the presuppositionalist framework. C.S. Lewis provided the apologetic template. The sociologist Peter Berger, the philosopher Thomas Nagel, the literary critic Flannery O'Connor, and the philosopher-theologian Alvin Plantinga all appear in the book. Keller was unusual among evangelical apologists in taking postmodern philosophy seriously and engaging with it rather than simply dismissing it.
Structure and Argument
Part 1 ('The Leap of Doubt') addresses objections: that there is only one true religion (Chapter 1), that a good God could not allow suffering (Chapter 2), that Christianity is a straitjacket for human freedom (Chapter 3), that the church has caused too much harm (Chapter 4), that a loving God could not send people to hell (Chapter 5), that scientific evolution makes God unnecessary (Chapter 6), and that the Bible is not historically reliable (Chapter 7).
Keller's method in Part 1 is not primarily defensive but offensive: he argues that each of these objections, when examined carefully, contains a hidden assumption that is itself not obviously true. The objection from suffering (Chapter 2) assumes that there is no conceivable reason why God would permit suffering - an assumption that requires omniscience to sustain. The objection from religious exclusivity (Chapter 1) assumes that it is wrong to claim exclusive truth - a claim that is itself exclusive and therefore self-refuting. The objection from evolution (Chapter 6) assumes that Darwinian evolution and Christian faith are incompatible - an assumption that the majority of professional biologists who are also practicing Christians would dispute.
The 'Interlude' between Parts 1 and 2 addresses the epistemology of doubt: 'All doubts, however skeptical and 'rational' they seem, are really a matter of faith.' Keller argues that doubt is not the alternative to faith but a form of it, and that everyone operates on unprovable faith commitments. This section draws on Alvin Plantinga's Reformed epistemology and on Ludwig Wittgenstein's claim that all questioning takes place within a framework that cannot itself be questioned.
Part 2 ('The Reasons for Faith') presents positive arguments: the clues of God in natural order, human consciousness, universal moral intuition, and human longing (Chapters 8-10); the historical case for the resurrection (Chapter 13); and the logic of Christianity's account of sin, the cross, and transformation (Chapters 11-12 and 14).
Critical Reception
The book was well-reviewed across a wide spectrum. The secular New Yorker published a lengthy profile of Keller acknowledging the book's intellectual seriousness. Evangelical scholars praised its engagement with contemporary philosophy and its accessibility. N.T. Wright called it 'a brilliant book' and endorsed its treatment of the resurrection.
Critics from the 'new atheist' side generally found the book more intellectually serious than most evangelical apologetics but questioned whether Keller's arguments, while sophisticated, successfully refuted the strongest secular objections. The philosopher of religion Keith Parsons disputed Keller's handling of the problem of evil. Bart Ehrman questioned his treatment of the Gospels' historical reliability.
Within evangelicalism, some Calvinists felt that Keller was too accommodating to postmodern epistemology and that his presuppositionalism was insufficiently rigorous. His broadly Reformed but irenic tone - he did not condemn non-Christians or even non-evangelical Christians - was seen by some as theological softness.
Theological Significance
The book's theological significance lies in its demonstration that Reformed theology and contemporary apologetics are not merely compatible but mutually reinforcing. Keller showed that the Calvinist heritage - with its robust account of common grace, natural revelation, and the noetic effects of sin - provides excellent resources for engaging secular intellectual culture.
His treatment of justice is particularly notable. Keller argues that the secular desire for justice - for the oppressor to be punished, for wrongs to be made right - is not in tension with Christianity but is fulfilled by it. The cross is not an obstacle to justice (as critics of penal substitution argue) but its supreme expression: God himself bears the full weight of human injustice, satisfying both the demands of justice and the demands of love. This synthesis of justice and love, drawn from Romans 3:21-26, is the theological heart of the book's apologetic strategy.
Legacy
Keller became the most influential evangelical thinker of the first two decades of the twenty-first century. His church planting organization, Redeemer City to City, has planted over nine hundred churches in global cities. His books - including The Prodigal God (2008), Counterfeit Gods (2009), Generous Justice (2010), and Center Church (2012) - developed different aspects of the theological vision in The Reason for God. His death in May 2023 was mourned across the entire spectrum of Protestant Christianity and by many outside it.
The Reason for God stands alongside Lewis's Mere Christianity and Chesterton's Orthodoxy as the third great apologetic landmark of English-language Christianity in the twentieth and twenty-first centuries.
Reading Alongside Scripture
Readers should study Acts 17:16-34 (Paul's Areopagus speech as the model for engaging secular culture), Romans 1:18-2:16 (natural revelation and the moral law), 1 Corinthians 1:18-25 (the apparent foolishness of the cross), Romans 3:21-26 (justification and the atonement), and John 18:33-38 (Pilate's 'What is truth?' and Jesus's answer).
Further Reading
- Collin Hansen, Timothy Keller: His Spiritual and Intellectual Formation (2023) - the definitive intellectual biography, with detailed attention to the sources of Keller's apologetic method. - Alvin Plantinga, Warranted Christian Belief (2000) - the philosophical foundation for the Reformed epistemology that Keller draws on in the 'Interlude' section. - N.T. Wright, The Resurrection of the Son of God (2003) - the scholarly source for the resurrection arguments that Keller presents in accessible form.