"Again, my point is not that people are neglectful or frivolous while serving on jury duty, but that they have problems separating fact from fiction when their religious beliefs enter the picture - and that happens all the time, given this country inundation with religious symbolism, invocations of god, or swearing on the bible."
Well, that's the thing about the people, they are just as good as they are, not as good as we want them to be.
The case for juries is not that they are perfect (nothing is) but that the people have less vested interests than special experts, judges or police chiefs. (And the underlying assumption is that common sense is not different substance from reason, but only a less refined reason, its rational component capable of being drawn out by cogent argument.)
If we are worried that people lack maturity, we are not going to change that by taking away their responsibility for important decisions.