Well, I tried to read this book today, and failed. It is one of the most poorly written things I've encountered in a long time. It is the worst combination of pointless dialogue combined with unoriginal, inaccurate, mind-numbing discussions of bible ideas. It is painfully long. I read for a long time and discovered I was only a quarter of the way through it. If it were a trade paperback, it would be about 200 pages long.
If this book does have something original to say, it takes so long to get to the point that I simply cannot endure the journey. Please drop me off here; I am done.
I have many problems with this book I haven't read through. One, that the author doesn't seem to think it necessary to explain at the outset what the book is about, and what its main premises and claims are. If he is going to try to re-purpose the gospel of Jesus Christ, then he owes his readers a huge debt of intellectual honesty and openness. It's also intellectually arrogant to assume that you have a message that is so extraordinary that it is permissible to bore and annoy your readers. In all the reading and browsing I did of this book, I don't even know what a "gospel enigma" is.
There are many books that have tried to do what this book claims to do, say, The Book of Mormon, or "Science and Health," or "A Course in Miracles," or any of the other religious books that claim they are going to provide a definitive (and new) exposition of the Word. This is dangerous ground, and is even spoken against in the Bible. We are not to add to or take away from the Word.
Let's attack this issue of revelation a bit. The word "enigma" concerns me, because it sounds vaguely gnostic. The word "enigma" means "mystery" or "secret." Gnosticism, simply put, means that one thinks there are secret or hidden spiritual truths that have to be "revealed" to you. I think the "hidden treasure" as mentioned in this book is an example of this book's claim that there is hidden spiritual truth that will be revealed only to the chosen ones. This is prideful, sinful, and warned against repeatedly in the new testament. Frankly, it's witchcraft.
Another problem I found as I (tried to) research this online, was that I couldn't really find any constructive information or criticism about the book. All I could find were these fanboys going on about how great it was, and about how "controversial" it is. The stranger thing is that I couldn't find anybody who was actually on the contra side of the controversy, only the pro side. Why can't I find any intelligent discussion of the ideas in this book? Quit acting like a bunch of mind-blinded zombies.
I hate to disappoint you, but being controversial is nothing more than old-fashioned rebellion, and is clearly sinful. We are commanded to avoid controversy in religious matters. If people are offended, it's important to find out why they are offended. They might be offended because they find the gospel being perverted.
In your question, you make a comment about "non-theological point of view." I see a straw man argument here: You are claiming that "Gospel Enigma" presents a pure point of view, and at the same time, you claim all "theologians" are cut from the same cloth and have the same errors and points of view. I'm no theologian, but I can think like a laser, thanks to God's blessings. And there are theological problems, and I think there are problems with much modern scholastic theology. But none of these errors of theology in any way justifies a book like this one, boring and full of falsehood.
I did notice that a character in the book made this weird side-comment that "we don't know who wrote the book of Hebrews," and continued by saying we shouldn't consider Paul an Apostle, because he didn't see Jesus. (Paul says Jesus revealed himself to him--remember, Jesus has a resurrected body). Such claims (Paul isn't a true apostle, he didn't see Jesus, he probably didn't write Hebrews) is gross, anti-bible falsehood, and even if these errors were corrected elsewhere in the tedious book, it is hugely problematic for a writer on Christianity to write dialogue about the Bible that makes false claims, even for the sake of exposition or story arc.
I'm upset all right. Upset because this book is painfully bad, a complete hack job, and contains falsehoods. I seriously doubt it has anything new or useful to say.
There's one more issue at hand. The tone of the book--its dumbed-down simplicity, its desire to try to rework all the things we currently understand about the Gospel--stinks of Emerging/Emergent church theology, which is an utter heresy that anybody who wants to go to heaven must carefully avoid. The truths of the gospel are many, and they are simple, and they are learned line upon line, precept upon precept, and they are lived in purity of body and mind and heart, and in faith in Jesus.
Do not use it as a reference. Use the Bible as your reference, and stop offending the Word.