John 1:1
Does the missing article require ‘a god’?
Begin with the context: Read John 1:1–18, with special attention to verses 1–3 and 14–18.
Ἐν ἀρχῇ ἦν ὁ λόγος, καὶ ὁ λόγος ἦν πρὸς τὸν θεόν, καὶ θεὸς ἦν ὁ λόγος.
Literal word-for-word: In beginning was the Word, and the Word was toward the God, and God was the Word.
The close gloss keeps the final clause in Greek order. It is not intended as polished English.
The NWT reads ‘the Word was a god.’ Faithful translations read ‘the Word was God.’
What the wording establishes
John distinguishes the Word from the One he was with, predicates theos of the Word, and then states that every created thing came into being through him.
What still requires interpretation
A mechanical gloss cannot settle the force of a preverbal predicate noun. Grammar, discourse, and John's complete presentation of the Word must govern the conclusion.