To add to the "why postulate anything as ethereal?"
Think about why we create the artificial construct that is currency. The actual physical stuff currency is made out of doesn't have much if any practical value (you can maybe burn it or wipe your rear with it). Yet we use it as an abstract representation of other things because it is more convenient to pretend these bits of paper have value than to trade and barter actual goods with actual practical value. It's an abstract idea we agree upon for a particular purpose. Metaphysical concepts in religions can have similar utility purpose.
Think about why we create the artificial construct that is currency. The actual physical stuff currency is made out of doesn't have much if any practical value (you can maybe burn it or wipe your rear with it). Yet we use it as an abstract representation of other things because it is more convenient to pretend these bits of paper have value than to trade and barter actual goods with actual practical value. It's an abstract idea we agree upon for a particular purpose. Metaphysical concepts in religions can have similar utility purpose.