Answer:
Almost everyone needs it, asks for it, gives it. But almost nobody takes it.
A precious gift, yet it has no end, no beginning, and nothing in the middle.
What loses its head every morning only to get it back every night?
If it is absolute, it will corrupt absolutely.
What always comes into the house through the keyhole?
I am the fountain from which no one can drink. For many I am considered a necessary link. Like gold to all I am sought for, but my continued death brings wealth for all to want more.