naomi, I worked pretty hard to answer your OP, and did - and even defined everything you asked me to! A bit of a shame that you would call me pathetic. To summarise ...
You defined a "rational reason" as one that provides "evidence". You defined evidence as "scientific evidence", i.e. evidence that conforms to the scientific method.
Together we then defined "supernatural" as "beyond scientific understanding"; so already we could have had a problem, as (by your definitions) requiring a "rational reason" for something "supernatural" is requiring scientific evidence for something beyond scientific understanding. This could prove problematic.
But it turned out that didn't matter because you then went on to further define "supernatural" as "impossible" - so even if any evidence was to be presented and accepted as possible, it could not possibly be accepted as supernatural, and therefore not evidence of a supernatural God.
At this point, as I said above, the OP may as well have used the word "cod" rather than "God". It really doesn't matter, since whatever God is, the "supernatural" adjective has marked it as impossible by your definition. You didn't have to include the word "supernatural" in the OP - it was implied by the word "God" anyway - but in including in there, you made doubly sure that the there was no room for debate. A real belt and braces approach.
I mentioned earlier that you had "poisoned the well" with the very question. See
http://en.wikipedia.o...ki/Poisoning_the_well for more details. The whole page is relevant, but note especially the section that starts "An even simpler example of poisoning the well is by tautology and definition, or circular reasoning."
So you set up the question in an attempt to favour an atheistic answer by using definitions to create tautological circular reasoning. Despite that, you still failed to answer the question yourself. Your own rational reason - which was "I have no evidence" - does not meet the scientific standards that you demand of theists. Absence of evidence is not evidence of absence - this is a logical fallacy, the argument from ignorance -
http://en.wikipedia.o...ument_from_ignorance. The response to this - not from you, but from other athesists on the thread - was that theists need to be held to a higher standard because their claims are so extraordinary. This is yet another logical fallacy, the argument from incredulity which is closely related to the argument from ignorance - so much so that's further down the same Wikipedia page, here:
http://en.wikipedia.o...2FLack_of_imagination
So what do we have?
* Poisoning the well
* Straw man argument
* Argument from ignorance
* Argument from incredulity
* Probably some others I glossed over
A litany of logical fallacies, ironically presented by people looking for rational responses.
I'm sure you could come up with rebuttals to all of the above, and I'm sure they'd make perfect rational sense to you, based on your own atheistic worldview - but probably not to me, even though my own worldview is far closer to atheist than theist! Some very smart people from all sides are paid to argue about this stuff, have argued long and hard about it, still can't agree on it, and probably never will, and I can't see this discussion being any different. I'm
not paid to argue about it and I've had enough of being told how I should think (generally by both theists and atheists, and specifically by atheists on this thread) , so I really will leave it there this time. I admit that you could be right about the existence of a God, and I accept that you don't think "I don't know" is the right answer to the question ...