How do spirits work? [I Religion]

One thing I never understood about spirits and the afterlife or whatever is, when we die and our spirit/soul leaves our body, we still have our senses right? Like sight, smell, touch, etc. Now I'm not exactly the smartest guy when it comes to biology but, aren't those things for..... A physical being? I meaaaaaan, in order to make those work we gotta pump nutrients and blood through it all right? Consciousness itself can't be what we become purely. How does a ghost brain work? How do ghost eyes work? What about our digestive systems?!?! Does matter even exist in the afterlife? WHY WOULD SUCH THINGS BE RELEVANT IF WE DO NOT REQUIRE SUSTENANCE FOR A NONPHYSICAL BEING?!?! I know people have differing opinions on the matter of spirits (obviously, Sherlock) but the usual depiction is that of just a regular [i]dooooood[/i] but a little ethereal or has clouds instead of feet... Idk... Fuhgetaboutit. ┬┴┬┴┤•ᴥ•ʔ/

Also I probably should've prefaced by saying I don't believe in ghosts or religion but hey, I'm still interested nonethelessssssssssssssssss.