This is not a time for Christians to turn the other cheek. Rather, it is a time to drive the money-changers out of the temple. The atheists no longer want to be tolerated. They want to monopolize the public square and to expel Christians from it. They want political questions like abortion to be divorced from religious and moral claims. They want to control school curricula so they can promote a secular ideology and undermine Christianity. They want to discredit the factual claims of religion, and they want to convince the rest of society that Christianity is not only mistaken but also evil. They blame religion for the crimes of history and for the ongoing conflicts in the world today. In short, they want to make religion—and especially the Christian religion—disappear from the face of the earth.

The Bible in Matthew 5:13-14 calls Christians to be the “salt of the earth” and the “light of the world.” Christians are called to make the world a better place. Today that means confronting the challenge of modern atheism and secularism. This book provides a kind of tool kit for Christians to meet this challenge. The Christianity defended here is not “fundamentalism” but rather traditional Christianity, what C. S. Lewis called “mere Christianity,” the common ground of beliefs between Protestants and Catholics. This Christianity is the real target of the secular assault.

I have written this book not only for believers but also for unbelievers. Many people aregenuine seekers. They sense there is something out there that provides a grounding and an ultimate explanation for their deepest questions, yet that something eludes them. They feel the need for a higher sense of purpose in their lives, but they are unsure where to find it. Even though they have heard about God and Christianity, they cannot reconcile religious belief with reason and science; faith seems unreasonable and therefore untenable. Moreover, they worry that religion has been and can be an unhealthy source of intolerance and fanaticism, as evidenced by the motives of the September 11 terrorists. These are all reasonable concerns, and I address them head-on in this book.