The word is only used in scripture to denote property, particularly of the father of the prodigal son, Luke 15:12. Elsewhere, Paul uses the word παρουσια, parousia, (para/ousia 'alongside substance') to convey his presence in body, as opposed to his being absent, Philippians 2:12.
But when Paul wishes to convey his presence in spirit (being absent in body) he uses the verb 'to be', employing the Greek word πάρειμι, pareimi (para-eimi 'alongside being').
Now, Jesus says quite emphatically that ... pneuma ho Theos ... Spirit, the Deity John 4:24, expressing an equivalence with neither a verb nor an article to reduce the force of that equivalence. And which we translate into English idiom as 'God is a Spirit'.
Then should we not, in referring to Deity, take heed of Paul's usage and not use ousia ('property' or 'substance') when referring to Him who is Spirit ? (This is a rhetorical question, for consideration, and is not part of my enquiry, as such.)
It seems to me that it may have caused confusion, historically, to bring in a concept of 'substance' rather than use Paul's wording ('to be' or, possibly, 'essence' - from the Latin) in referring to God.
Did any of the Early Church Fathers, particularly at the time of the Council of Nicea, recognise this distinction, or did all accept the philosophical meaning of the term ousia, as emphasised by Greek philosophers ?