can a verb be a state being. Such as, love, exist, believe

I think "state" verbs are different from "state of being" verbs

Some state verbs - love / know / concern / believe / think

Be verbs - be / am / is /are / was / were / being / been

Yes a verb can be a "state of being" such as think, believe, love, feel, dream, and exist

No, love is a state verb.

The "state of BEing" verbs are simply the 8 forms of "to be" - am, is, are, was, were, being, been, be.

Note that the last three always require a helping verb (ex: He was being... I have been... Will you be...)

Science fiction author Robert Heinlein defined "love" this way;

Love is the state of mind in which another person's happiness and well-being is more important to you than your own happiness and well-being.