John 1:1c, "a god" and Isaiah 43:10
Some might bring up for discussion Isaiah 43:10 where according to the NWT we can read:
"'You are my witnesses,' is the utterance of Jehovah, "even my servant whom I have chosen, in order that you may know and have faith in me, and that you may understand that I am the same One. Before me there was no God formed, and after me there continued to be none. I - I am Jehovah, and besides me there is no saviour'"
We would benefit from noting the context. Jehovah is asking his witnesses, the nation of Israel, to consider the "gods" of the surrounding nations. In contrast to Jehovah, the God of Israel, these gods have no real power as Jehovah has and has shown throughout this nation's history. Really, these pagan, idol "gods" are non-existent, an unreality.(Is.41:23) Hence, it is truth that Jehovah alone is the true God. There are no others that can rival him or can be compared with him from amongst the pagan nations. However, as can be seen from our discussion of the word "god"(Heb."elohim"), others who are not false "gods" can be so described. So there are more than just the two 'categories' or usages of "God/god" than a) The True God and b) False gods. There is another: c) Those who are both representatives and reflections, with power and authority from the True God can also be termed "god/gods." John, in his opening verses to his Gospel therein describes the Word, in his prehuman existence, as, not a false, idol, non-existent "god," but as one who was with the True God, and as 'spokesman' of this One, could be properly described as a "god." There is therefore, when we consider the contexts of both passages, no conflict with Isaiah 43:10 and the NWT's rendering of John 1:1.
We should carefully note what Jehovah says here at Isaiah 43.11.
Jehovah states that besides He there is "no saviour." Is this true? Yes, of course. We can also read at Isaiah 12.2 "Look! God is my[Israel's] salvation. I shall trust and be in no dread; for Jah Jehovah is my strength and my might, and he came to be the salvation of me." However does not the scriptures themselves call others, other than Jehovah, "saviours"? Yes! For instance see Judges 3.9. Was Othniel a "saviour"? Yes. Was Othniel a 'false' saviour? Of course not! This shows that Jehovah can state that only he is a "saviour" of his people yet at the same time call others who he uses, by 'raising them up' for purposes of salvation, "saviours." Hence, it would be wrong for someone to argue that only Jehovah can be a "saviour" because of what we read at v.11 of Isaiah 43. It would be equally erroneous then to argue that because Jehovah stated that "Does there exist a God beside me? No, there is no Rock. I have recognized none" (Is.44.8) that Jehovah Himself can not call into existence those who he would recognise as a "god" or "gods" and yet these are not in any way 'false' or non-existent. Note that Jehovah says he "recognises none."-Is.44.8. That is, Jehovah does not "recognise" any of the nations "gods." Jehovah is the only absolute "God" and only those he calls "gods" or "a god" would he "recognise" as such. This is what Israel was to recognise: That He was a God in whom there is no rival from the nations "gods." None of these were "saviours" of Israel nor were any of these "gods" who were "beside" Jehovah. Those who bring up Isaiah 43.10 to argue against a grammatically and contextually correct translation of John 1.1c ("and the Word was a god"-NWT)are only showing that they have mis-understood the context and hence mis-aplying it in support of a trinitarian understanding of theos at John 1.1 and at the same time showing that they have to resort to such a misunderstanding because of the strength of the grammatical arguements that favour the "Word" there being described, no, not as "God," but as "a god" who was with "God."
For a more complete discussion of this question I would urge those who are really interested to seek out the 'article', Question From Readers',The Watchtower, July 1st, 1986, p.31