I just run the software here, I'm no Greek expert, but here's how I understand it.
First, the verse:
John 1:1 wrote:Ἐν ἀρχῇ ἦν ὁ λόγος, καὶ ὁ λόγος ἦν πρὸς τὸν θεόν, καὶ θεὸς ἦν ὁ λόγος.
There's no article before ἀρχῇ, there's no article before θεὸς in θεὸς ἦν ὁ λόγος.
Whereas the article has a clear meaning, the lack of an article has no clear meaning. For instance, in John 1:1, ἀρχῇ clearly refers to "the beginning", not to "a beginning":
Grammatically, there are three possible ways to interpret καὶ θεὸς ἦν ὁ λόγος:
"And the word was God" - the translation found in most traditional Bibles.
"And the word was a god"
"And the word was divine"
Since Greek grammar permits each of these meanings, you have to look at the context and the belief system of the writer in order to understand which meaning is most likely. For instance, I think it's very relevant that John also says this, using the article for ὁ κύριός and ὁ θεός.
ἀπεκρίθη Θωμᾶς καὶ εἶπεν αὐτῷ· ὁ κύριός μου καὶ ὁ θεός μου.
But there's another issue: with titles like κύριος or θεὸς or βασιλεως, the title itself often implies a definite meaning. So βαλλα βασιλεως σοδομων means "Birsha, King of Sodom" (qualitative, emphasizing the nature of exercising kingship) or "Birsha, the King of Sodom (definite, 'the King')", and there's no real distance between the two meanings.
Similarly, the common phrase κύριος ὁ θεὸς means "The Lord God", clearly not "God, a Lord (one of many)".
ἐξίσταντο δὲ πάντες καὶ διηποροῦντο, ἄλλος πρὸς ἄλλον λέγοντες, τί θέλει τοῦτο εἶναι;