"In rejecting an organized religion, why make a leap to rejecting the entire inquiry?"
They spoiled it for us.
But if you're serious^H^H^H^H^H^H^Hrational in your inquiry, you'll come to discover that, like Santa Claus, God does not exist, at which point you will also reject the inquiry. All of it.
Belief in God and belief in Santa Claus are not equivalent. There is no reason inherent in usual descriptions of Santa Claus that one would expect him not to show up on radar, for example, so you can take his absence as evidence of nonexistence. While there are a lot of specifics in the Bible that can be similarly tested, the usual view of (non-fundamentalist) Christians today is that the miracles and such aren't necessarily literal, so there's nothing to test: belief in God-the-Creator is a given, and no amount of evidence or reason can legitimately sway a believer to disbelieve, or a non-believer to believe.
Indeed; I'm familiar with this. If you believe in the Christian God, it's possible to rationally assert that no test can prove Him, but that after death everyone will know that He exists.
The simulation argument, linked to recently here, I believe, has much the same features without the religious baggage: there is no experiment you can do which will provide direct evidence that you are, or are not, in a simulation. In the extreme case, the simulators could just stop the sim, back up, and change the outcome of the experiment (or just your perception of the outcome), and continue on.
However, it might still be important to your future survival whether you act as though you are or are not in one, in either case.
Unfortunately, you first have to define something before you can say whether it exists. And a proof for God has remained elusive. Santa Claus I don't know about because I never believed in him (or the Easter Bunny!).
Still, there are some definitions you might offer for God that I'd agree with. And your conclusion would be to reject the existence. Mine would be to ask for better a definition.
They spoiled it for us.
But if you're serious^H^H^H^H^H^H^Hrational in your inquiry, you'll come to discover that, like Santa Claus, God does not exist, at which point you will also reject the inquiry. All of it.