being vs existence

being and existence both are nouns.

Word	Noun	Adjective	Verb	Adverb
being	Yes	No	No	No
existence	Yes	No	No	No

As nouns, being and existence are synonyms defined as:

Other synonyms of being include beingness, face of the earth.

being (noun)	existence (noun)
a living thing that has (or can develop) the ability to act or function independently	everything that exists anywhere
the state or fact of existing	the state or fact of existing