Timothy Keller’s The Reason for God, published a few years ago, was an excellent exposition of reasons to believe in God and Christianity. Now Keller has followed up with what could be called a prequel, Making Sense of God, addressing those sceptics who see Christianity as so implausible that no rational person could even consider it. His aim is to show that Christianity is worth investigating.

Keller’s approach is to firstly compare the foundations of Christianity and secularism – the latter being the view that denies the existence of a supernatural realm and is concerned with the here-and-now. He begins by challenging the idea that religious belief is inevitably declining, citing statistics that show Christianity is thriving in the non-Western world. Many people sense that secular reason does not provide a sound basis for meaning and virtue, and fails to explain the widespread perception that there is more to life than just the material.

Keller goes on to expose the flaws in the narrative that claims the religious live by blind faith, while non-believers ground their position in evidence and reason. All reason depends on faith in our cognitive faculties, and the belief that science is the only arbiter of truth is itself not a scientific belief. No-one can “assume an objective, belief-free, pure openness to objective evidence”. Instead, we all operate based on a set of tacit assumptions about reality that we are not consciously aware of. In fact, secular humanism’s values can be traced back to its Jewish and Christian roots.

This means that instead of asking religious people to prove their beliefs, we need to compare religious and secular beliefs based on their evidence, consistency, and success in accounting for our experiences. Keller spends the majority of the remainder of the book performing this comparison.

Firstly, Keller notes the disdain postmodern culture treats having meaning in life. In an indifferent universe, the only meaning is that which we make ourselves. These created meanings can serve us well, and we must not tell secular friends their lives have no meaning. But he points out that created meanings are ultimately insignificant when the big picture is considered, and are impotent in the face of personal suffering. By contrast, Christianity claims there is objective, eternal Meaning that can be discovered, and teaches that suffering is a terrible reality that can still have purpose.

Meaning is linked to happiness and satisfaction in life, Keller’s next point of comparison. Despite the advances we’ve made in science, technology and medicine, we are not any happier. The ephemeral nature of satisfaction and our desire for something that the world cannot supply points to our being “made for another world” as C.S. Lewis famously put it. Keller draws on Augustine’s insight that dissatisfaction and discontentment is a consequence of our failure to love God first and foremost. If we love anything more than God, it will become the source of our happiness, and will eventually fail us.

People have always valued freedom, but in secular societies freedom has become the ultimate good. Freedom is now understood as the “right of the individual to choose his or her values”, and we can live as we see fit. Keller rightly notes that a focus on individual freedom has in many instances led to a fairer society, but thinks the narrative has gone awry. It has produced the “harm principle”, where we believe we should be free to live as we please as long as we don’t harm anyone else. But this is disingenuous, because the notion of harm is dependent on what a good human life consists of – and that is a matter of our subjective beliefs.

Also, an extreme focus on individual freedom and personal fulfilment actually threatens freedom itself, as self-absorbed individuals undermine communities and democratic institutions. According to Robert Belah, “the health of a society depends on voluntarily unselfish behavior” which involves infringing on our personal freedom. Paradoxically, we also find most happiness in our relationships, where we sacrifice our freedoms for the other. So absolute freedom is not an end in itself, but rather a means to an end. But what is that end? Keller has already explained the issues with deriving meaning and satisfaction from created things. If we consider that we are created by God, then God has determined our purpose and the constraints we should live by. And as in all relationships, both parties sacrifice their freedoms, God having done so by Jesus Christ becoming mortal and dying for us.

In chapter six, Keller moves on to our personal identity, noting the differences between the traditional concept of the self being “defined and shaped by both internal desires and external social roles and ties” and our modern, Western identity based on individualism and detachment. Like the focus on individual freedom, this has enabled considerable good, such as preparing American culture for the civil rights movement. But modern identity is also problematic. Our desires are constantly changing and often contradictory, and we can’t base our sense of who we are on them. We have to filter our desires based on a set of beliefs and values, and they are obtained (mostly unconsciously) from our culture and community. Unfortunately, modern society “adulates winners and despises losers, showing contempt for weakness”, and this makes our self-worth a fragile thing. Even if we eschew material success and base our identity on the love of another, if this is lost we will be devastated.

By contrast the Christian approach to identity is based on unconditional acceptance by God. Our worth is based on the value God has placed on us, not on achievements, race or relationships – or even our efforts to be moral. But this requires humility, and includes giving up our rights to our freedoms. Keller claims that a consequence of this acceptance is the ability to freely enjoy other identity factors such as race, work, family and community ties, and this is why Christianity is by far the most culturally diverse of all religions. He offers the example of African identity, the core of which is a belief that the world is full of evil and good spirits. Secularism rejects such beliefs, while Christianity accepts this understanding of the world, and offers a solution to the problem of how one can be protected from evil spirits.

Traditionally secularism has believed in the idea of progress, but optimism is beginning to crumble in the light of issues such as climate change.But humans are future-focused, and we need hope. But where can we find it? On the individual level, death is the end of all hope. If human relationships are what makes our life meaningful , death destroys them. But this is the message of Christianity – that there is hope beyond death, that love will survive. This hope is based in the reality of the resurrection of Jesus, who has defeated death for us.

Finally, Keller examines the problem of moral obligation. Secularism struggles to give an account of moral facts or even what comprises “good”, despite secularists having strong moral opinions. In what is probably his strongest chapter, Keller introduces the moral argument for God’s existence, noting that it has influenced many sceptical friends. He notes that human rights are far from self-evident, and that Christianity offers the strongest foundation for them.

Keller then goes on to ask which of secularism or religion provides the better foundation for human rights. Secularism’s best case is that they are self-evident, while Christianity claims our worth is based on our having God’s image within us, giving every human being dignity no matter what their capacity.When it comes to justice, secularism struggles without universal, objective values that religion can provide. Yes, there is the danger of becoming the oppressors when confronting oppression, and Christianity has often done so, but this has always contradicted the gospel.

In his final chapters, Keller reviews his comparison of secularism and Christianity, and concludes that Christianity offers a far superior narrative. In terms of key facets of human life, meaning, satisfaction, freedom, identity, hope and justice, Christianity makes sense. It is worth considering. But is it true? To answer that question, Keller offers a concise summary of the arguments presented in The Reason for God. He concludes with Langdon Gilkey’s powerful story of selfishness in a Second World War prison camp, where rationality proved insufficient as a basis for moral obligation when resources were scarce. Instead, people saw no reason to be unselfish, and it was the rare person who could self-sacrifice. Gilkey concluded that only faith in God, exemplified by former Olympic athlete Eric Liddell who was interred in the camp, enabled people to be truly unselfish in such circumstances.

Will Making Sense of God convince secularists to take a deeper look at the arguments for Christianity? If they are willing to put serious effort into their reading of Keller, it certainly should. It does a thorough job of exposing the assumptions secularism makes about reality, which should make anyone demanding “evidence” for the existence of God a little more cautious in their assertions. Keller’s comparison of secularism and Christianity is thorough and well-researched, drawing on broad range of scholarly sources. Charles Taylor’s A Secular Age is a key reference, and for readers unfamiliar with this work, it would be worth reading James K. A . Smith’s How (Not) to Be Secular: Reading Charles Taylor.

Making Sense of God is not an easy read. Keller covers a lot of ground, and references many philosophical concepts that some readers may not be familiar with. Secularists will find it challenging to their worldview, while Christians will find it intensely rewarding.

Timothy Keller discusses Making Sense of God in a Mere Fidelity podcast here.