I understand logic just fine. That's why I have such an easy time recognizing silly illogic and trolling when I encounter it.
So how exactly is answering a challenge trolling? At best, that opinion is only subjective because you find my answer somehow offensive.
Let's go ahead and suppose that's true, for the purposes of this thread.
What you've missed in your haste to troll, is that the implications cut both ways - for a believer to "affirm the basis of his ethical system" is necessarily for him to attack the basis of the ethical system of all non-believers, and all believers in alternative theologies. This is then clearly immoral, as per your insistence, and so you haven't managed to construct an ethical act that is available to believers but not to non-believers. The situation is, in fact, perfectly symmetric, just as Hitchens contended.
That would merely be an inferred negation based on a positive assertion. It is not necessarily implied by the positive statement. The positive assertion does not itself constitute a refutation of another proposition. The divine and reason is not a mutually exclusive dichotomy. Quite the contrary, just as I've said, a believer is capable of agreeing with the reasons for a non-believer's ethics. Asserting his own divine basis does not itself refute a reasoning, and thus allows agreement in this direction.
So the only symmetry here is assumed in the haste of your own trolling.
Oh dear... I recommend you try to stay out of the deep end. You're already in way over your head without getting into things like determinism.
Affected condescension will get you nowhere.
No, that's silly. If a believer "honestly agrees" with an atheistic, "pragmatic" basis for ethics, then he is clearly stating that he doesn't not honestly hold any theological basis for his own ethical system, and so is disqualified from the category of "believer."
What you could assert is that a believer is capable of recognizing that there are alternative bases for ethical systems that produce workable results. But then, so could an atheist. There is no asymmetry here.
No. As I just said, the two are not mutually exclusive, so faith doesn't deny such reason while such reason does deny faith. You must show how faith and reason are completely and mutually exclusive in order to support such a symmetry. While these two definitely have varying degrees of conflict and compatibility, it is a false dichotomy to claim they are mutually exclusive.
I think you'll find that atheists don't generally have well-developed, complete, detailed logical systems of ethics that precede their morality. And not do theists.
Do you really believe that a given religionist would suddenly become unclear on whether it is immoral to kill, or rape, or steal, if he were to encounter serious doubts as to his theology? I don't. I contend that he probably knew all those things were wrong well before he came to possess any recognizable theology. Indeed, human history is replete with people shifting between different theologies (or none at all) without any apparent consequences for their moral systems.
Finally, let's note that your whole premise in the OP - that theists are can recognize the "pragmatic" functionality of atheist ethical systems - argues directly that the final ethical system doesn't depend on the theological "basis" (or lack thereof) in any strong way, and so there is no inherent impact on said ethical systems in challenging said "basis," whatever it may be.
People, especially adolescents, quite often rebel against former moralities in ways which include the blatant breaking of secular laws and other normative societal ethics. There are also plenty of people who do not seem to have a native empathy with which to inform any intuitive morality.
Any supposed "final ethical system" does nothing to alleviate the vacuum of a basis or authority when a morality is undermined. There is an inherent impact which postulating some distant future only avoids. And yet again, faith doesn't necessitate an absolute exclusion of reason. Any such "final ethics" is not incompatible with maintaining a divine basis.