Jason Boyett:

[D]oubt is a necessary part of faith. We tend to think that faith and doubt are opposites, but they're not. The opposite of faith isn't doubt. The opposite of faith is certainty. If we are certain of something, we don't need faith. Faith and doubt, then, exist side by side -- and that plays itself out all over the Bible ("Lord I believe! Help me overcome my unbelief.").

But -- reason #2 -- doubt is about as taboo a subject as you can bring up in church. When was the last time anyone in a small group or church service admitted to not knowing if he or she believed in God? Or wondering if God was really present at all, or good? I've honestly had readers tell me that they'd love to read my book, but worry about what their friends or family might think when they see them reading a book about doubt. It sounds flippant, but maybe they should hide my book behind a Playboy. It's more acceptable to be a Christian with a porn problem than a Christian with a doubt problem. That's horrible. I want doubters to know that they're not alone in the journey, and that it's OK. That they don't have to pretend to have it all together. That they don't have to fake it. I hope this book gives them the freedom to be honest, and the encouragement to continue pursuing God, however that might look.