From the preface of Christianity for Doubters:

Of course, you do not have to believe anything in chapters 3-6 of this book or anything in the Bible to believe in intelligent design; pre-Columbian American Indians, for example, had never heard of the Bible, yet most of them believed plants and animals were designed. In fact, some intelligent design advocates are uncomfortable with a book that combines chapters on intelligent design with explicitly Christian chapters because it might encourage those who claim that ID proponents do not understand the difference between science and religion. Most of us do understand the difference; we are just interested in both.
 
And so are ID critics. In fact, I have been making the case for ID for many years, and my experience has convinced me that most of the angriest critics of intelligent design will never be persuaded by logic or evidence because their opposition to ID is based primarily on religious convictions. In a June 15, 2012, post at www.evolutionnews.org, Max Planck Institute biologist W. E. Lönnig said “Normally the better your arguments are, the more people open their minds to your theory, but with ID, the better your arguments are, the more they close their minds, and the angrier they become. This is science upside down.”
 
This has been my experience as well; these angry opponents of ID, at least in the Western world, do not really have trouble seeing the obvious evidence for design in the living world. They simply have problems with the Bible, which they see as the primary competition on origins, and find Christianity—as they have been taught it—unattractive, and so they prefer materialist explanations of origins, no matter how implausible. For these people, just presenting the scientific evidence for intelligent design in Nature, as done in chapters 1-2, is not sufficient. They need answers for the more difficult theological questions, which I have attempted to address in the final chapters.