Harner helped revolutionize our understanding of this grammatical
construction and thus went farther than what Colwell did. Colwell was
concerned about whether Jo 1:1c made θεος a definite or an indefinite
noun. Harner showed that it was neither.
I don't think that a count noun as the noun "theos" can lose its definiteness or its indefiniteness on account of its predicative position in a copulative sentence. I doubt that a common greek reader of the second century could grasp the difference between "kai theos hn ho logos" and "kai ho logos hn theos". So, I think that it is an anachronism to state that the position of the predicate eliminate the definiteness or the indefiniteness of the noun "theos".
It is very important to listen how a common greek reader understood naturally the sentence. Origen, commented what was the common confusion in the in the third century about John 1:1:
Now there are many who are sincerely concerned about religion, and who fall here into great perplexity. They are afraid that they may be proclaiming two Gods, and their fear drives them into doctrines which are false and wicked. (Origen, Commentary on John, book II, chapter II)
So, the many greek readers understood the anarthrous "theos" in John 1:1c as indefinite, because it is a count noun, not a mass noun. Of course, it caused terrible theological implications, because it affected the concept of the existence of "one and only true God". But we don't know what the writer of the first chapter of the Gospel of John had in mind. May be he was influenced by Philo's theology.
