The author is the ABC News physician and journalist (like Luke!). This is a very ambitious book, and generally quite good, marred only by a little political correctness and quickness to criticize religious conservatives and the rich (but I shouldn’t overstate that: on the big questions, he comes down the right way, believing in God, the Resurrection, Scripture, and so forth — he is a minister, after all).
Section 1 discusses the scientific evidence for God, section 2 is about the evidence for Jesus and who He was and what He means, and section 3 is about what all this means for how we should live. In the book’s last paragraph, the author announces that he has decided to leave ABC News and devote his life to more “direct service” in order better to “be a follower of Jesus.” He has a useful list of suggested reading.
Postscript: The separation of section 1 from section 2 parallels the approach I take in my short essay “Why I Am a Christian (and You Should Be, Too), in 600 Words,” elsewhere on this site. Likewise, the separation of section 3 from the other two sections parallels this site’s item on “Three Challenges.”