an attempt at a theological response
cdevidal says he won't return here, but for the benefit of innocent by-standers, I would like to offer my point of view. (home sick today and allowing myself all manner of wasted time)
My guess is that cdevidal is pretty young. At any rate, he is immature, both socially and spiritually. He's careless about his language in a public forum, thereby subjecting his faith (and mine) to public scorn. He refuses to acknowledge that his comments are hurtful to some, and imprudent for purposes of winning over others.
That said, I commend his desire to think about the use of GTD and his faith. Despite his other flaws, as I see them, this does speak of a desire for integrity (in the sense of wholeness, an undivided state, or unity of character).
The claim that GTD is purely secular is not a good answer to cdevidal's question. If the God that he says he believes in actually exists, then nothing is purely secular, as the term is used today. Look up the Latin origins of the word to see what I mean; this world is no less God's world, theologically speaking.
But, also, if the God that he says he believes in exists, then this God's attributes and works speak to his question. Everything that is, is good because created by God. That's not to say that the truths and principles captured in GTD, or anywhere else for that matter, cannot be misused. They can be. And that's not to say that they are neutral. They're not. They are good but can be misused.
I happen to hold to a demonological conception not completely different from cdevidal's. The difference is probably this. While I believe in personal spirits, good and evil, I also believe that anything can become a de facto "god" or idol when it takes a higher place in the divinely-established order of things than it ought, and I think that's the real issue here. Some readers probably know of GTD fans that build their lives around GTD to an extent that DA himself would disown. (Remember the SNL sketch where William Shatner visited a Trekkie convention and told them all to get a life?)
We're not Manicheans, cdevidal, my friend. The battle we wage is not between relatively balanced forces of good and evil. Anything given over to evil is stolen, and misused, not evil by design. GTD's full of good advice. And all truth is God's truth.
So it is truthfully written, "To the pure, all things are pure."