Skepticism has an underlying philosophy of "the more you learn, the more you realize how little you know". Keller missed that entirely in his book by claiming skepticism has to replace the concern for how little we know with faith. Seems disingenuous yet all the reviews here felt they approach skepticism with a viable response.
I also question the validity of the topics because believers in the Christian faith absolutely believe the scripture/bible/god as absolute truth yet it seemed apparent from me that Keller tried to stray from making such claims going so far as to say that all religions can have truth. How do Christians answer to the absolute they hold so dear that invalidates their reason for faith and how does this book answer to skepticism when it doesn't even recognize the philosophical views of skeptics to begin with?