οι πνευματι θεω λατρευοντες [TR]
who in spirit God worshipping [literal]
Pneumati is dative, thus locative, and 'in' is added for English idiom. (1)
Latreuontes is the nominative, plural, masculine, present participle. (1)
This is rendered 'who in spirit God serve' (EGNT - The Englishman's Greek New Testament) and 'who by the spirit are serving God' (YLT - Young's Literal Translation) and 'which worship God in the spirit' (KJV).
The object of worship (or service) is God. The mode of worship is 'in spirit'.
There is no reason to suppose more than is stated in the text. If one wishes 'proof of personhood and divinity', one must look elsewhere.
This particular text, as it stands, comments only on the mode of worship. The object of worship is stated to be Deity (as to nature) but the person worshipped is not defined.
I am only commenting on the Greek of the Received Text.
The Critical Text 'oi pneumati Theou (genitive) latreountes' ('who worshipping spirit of God' - sic) mimics 'en saki pepeoithotes' (in flesh having confidence, Phil 3:3b) and, to me, becomes incomprehensible without an article, thus casting doubt on the source.
(1) Bagster's Analytical Greek Concordance.