here we go again.

i never was, am
yet to be,
no one ever saw me,
nor ever will,
and yet, i am the
hope of all
to live and breathe on earth.
what am i?

the man who invented it doesn't want it,
the man who bought it doesn't need it.
the man who needs it doesn't know it.
what am i?

from the beginning of eternety
to the end of time and space
to the beginning of every end and the end of every place.
what am i?

(last)
in a marble hall white as milk
lined with sking as soft as silk
withing a fountain crystal-clear
a golden apple doth appear
no doors there are to this stronghold,
yet thieves break in to steal it's gold.
(mother goose LOL)

what is it?