Answer:
Rotten trees and Jack-O-Lanterns have this characteristic in common.
The more you look at it, The less you see.
What gives life and love, and is there till they die? What can hide you and find you, heal you and feed you but should never give up on you?
What is broken if you say its name?
It is in every mountain, it's not in any hill, it's not in all the world, and yet it's in the mill.
What is always coming but never arrives?