Janeway must reject her “belief” in science and totally embrace blind faith in order to cure Kes, which is insane on every possible level, but it works because it’s television. The Star Trek: Voyager Rewatch stomps all over “Sacred Ground.”
One of the hallmarks of Star Trek is its rationalism, though rarely as a substitute for faith. Worf and Kira (to give two examples) could still be very spiritual, could still have faith in their particular beliefs, but it didn’t make them idiots who rejected science, and it didn’t put them at odds with characters who were not spiritual.
In “Sacred Ground,” though, the entire episode is built toward getting Janeway to cast aside her “belief” in science, to take a leap of faith instead.
Here’s the thing: science isn’t a belief. The stupid and dangerous notion that science is a matter of belief and faith is why there are idiots walking around right now not wearing masks even though there’s a virulent pandemic floating around in the air.