In Greek, and in the context of 1st century Jewish and Hellenistic metaphysics, the language of the Prologue to John's gospel is nowhere near as definitive as translations often make it seem.
The term Logos had acquired a very particular religious significance as well. For Philo of Alexandria, it infers a kind of 'second-order divinity,' the mediating principle between God the Most High and creation. In late antiquity, in pagan, Jewish and Christian circles, God as the absolute transcendent does not engage with the world directly. God's presence in the world was seen as theophany (Gk theophaneia, 'appearance of God'), as a manifestation of His presence in sensible and thus accessible form.
The Logos was, to many Jews and Christians, the subject of all the divine theophanies of Hebrew scripture. Many early Christian apologists thought of God’s Logos as having been generated just prior to creation, in order to act as God’s artisan and administrator of the created order. (This question of the Logos' origin was central to the Arian dispute.)
From early on, theologians differed in their interpretation of John 1:1 because of the absence, perhaps a significant absence, of the article.
As Hart points out, "the article is omitted in the latter case simply because the word theos functions as a predicate there, and typically in Greek the predicate would need no article. Yet this rule tends not to hold when the predication is one of personal identity; moreover, the syntax is ambiguous as regards which substantive should be regarded as the subject and which the predicate; though Greek is an inflected language, and hence more syntactically malleable than modern Western tongues, the order of words is not a matter of complete indifference; and one might even translate καὶ θεὸς ἦν ὁ λόγος (kai theos én ho logos) as "and (this) god was the Logos." But the issue becomes at once both clearer and more inadjudicable at verse 18, where again the designation of the Son is theos without the article, and there the word is unquestionably the subject of the sentence." (Hart, New Testament, Postscript, p534)
I cite at length because Hart treats the problem fairly, purely as a matter of linguistics, rather than in the sense of a theological apologia.
John 1:18:
θεον ουδεις εωρακεν πωποτε ο μονογενης υιος ο ων εις τον κολπον του πατρος εκεινος εξηγησατο
(The) god no one has ever seen. The only-begotten/unique son, the (one) who is in the bosom of the father, that (one) declared (him).
'Only begotten' is the translation of the Greek monogenēs, but the emphasis is on unique, the only one of a kind, class or relationship.
John 10:33-36 (Hart translation)
The Judaeans answered him, "We stone you not on account of a good work, but rather on account of blasphemy, and because you who are a man make yourself out to be (a) god. Jesus answered them, "Is it not written in your Law 'I said, "You are gods"'? If he called gods those to whom God's Logos (ὁ λόγος θεός / ho logos theos came, and the scripture cannot be dissolved, how is it that, because I have said I am the Son of God, you say, 'You blaspheme' to one whom the Father sanctified and sent out into the cosmos?"
The Greek ho logos theos, in most translations, is "the word of God" and the Greek γίνομαι gínomai is 'came', but the more precise translation would be, from the verb 'to cause to be', "to whom God's word happened" or "with whom God's Logos was."
Again the Latin Verbum 'word' is insufficient with regard to the Greek Logos, as the mediator between the transcendent God and the cosmos.
So in these verses Jesus draws a closer union between himself as Son of the Father, v18 having already expressly stated that Jesus as Logos of God is one-of-a-kind and alone in his class of being.
Finally, we have John 20:28
και απεκριθη θωμας και ειπεν αυτω ο κυριος μου και ο θεος μου
kai thōmas apokrinomai kai eipon autos mou kyrios kai mou theos
and Thomas answered and said to him, my lord and my God!
Thomas addresses Jesus as ho theos, which unambiguously means the God, the One True God, God in the absolute sense.
He also says ho kyrios, again with the honorific article, which is the Septuagint rendering of the Hebrew Adonai, the preferred textual circumlocution for God's unutterable name.
Some scholars hold that this was the original ending of the Gospel, as it reaches a natural conclusion at this point. The last chapter then is a later addition, a kind of theological postscript that ties in with the theological prologue.
The point being, if John is uncertain or expressing any uncertainty in 1:1, then that is entirely and unequivocally resolved in 20:28.
The term Logos had acquired a very particular religious significance as well. For Philo of Alexandria, it infers a kind of 'second-order divinity,' the mediating principle between God the Most High and creation. In late antiquity, in pagan, Jewish and Christian circles, God as the absolute transcendent does not engage with the world directly. God's presence in the world was seen as theophany (Gk theophaneia, 'appearance of God'), as a manifestation of His presence in sensible and thus accessible form.
The Logos was, to many Jews and Christians, the subject of all the divine theophanies of Hebrew scripture. Many early Christian apologists thought of God’s Logos as having been generated just prior to creation, in order to act as God’s artisan and administrator of the created order. (This question of the Logos' origin was central to the Arian dispute.)
From early on, theologians differed in their interpretation of John 1:1 because of the absence, perhaps a significant absence, of the article.
As Hart points out, "the article is omitted in the latter case simply because the word theos functions as a predicate there, and typically in Greek the predicate would need no article. Yet this rule tends not to hold when the predication is one of personal identity; moreover, the syntax is ambiguous as regards which substantive should be regarded as the subject and which the predicate; though Greek is an inflected language, and hence more syntactically malleable than modern Western tongues, the order of words is not a matter of complete indifference; and one might even translate καὶ θεὸς ἦν ὁ λόγος (kai theos én ho logos) as "and (this) god was the Logos." But the issue becomes at once both clearer and more inadjudicable at verse 18, where again the designation of the Son is theos without the article, and there the word is unquestionably the subject of the sentence." (Hart, New Testament, Postscript, p534)
I cite at length because Hart treats the problem fairly, purely as a matter of linguistics, rather than in the sense of a theological apologia.
John 1:18:
θεον ουδεις εωρακεν πωποτε ο μονογενης υιος ο ων εις τον κολπον του πατρος εκεινος εξηγησατο
(The) god no one has ever seen. The only-begotten/unique son, the (one) who is in the bosom of the father, that (one) declared (him).
'Only begotten' is the translation of the Greek monogenēs, but the emphasis is on unique, the only one of a kind, class or relationship.
John 10:33-36 (Hart translation)
The Judaeans answered him, "We stone you not on account of a good work, but rather on account of blasphemy, and because you who are a man make yourself out to be (a) god. Jesus answered them, "Is it not written in your Law 'I said, "You are gods"'? If he called gods those to whom God's Logos (ὁ λόγος θεός / ho logos theos came, and the scripture cannot be dissolved, how is it that, because I have said I am the Son of God, you say, 'You blaspheme' to one whom the Father sanctified and sent out into the cosmos?"
The Greek ho logos theos, in most translations, is "the word of God" and the Greek γίνομαι gínomai is 'came', but the more precise translation would be, from the verb 'to cause to be', "to whom God's word happened" or "with whom God's Logos was."
Again the Latin Verbum 'word' is insufficient with regard to the Greek Logos, as the mediator between the transcendent God and the cosmos.
So in these verses Jesus draws a closer union between himself as Son of the Father, v18 having already expressly stated that Jesus as Logos of God is one-of-a-kind and alone in his class of being.
Finally, we have John 20:28
και απεκριθη θωμας και ειπεν αυτω ο κυριος μου και ο θεος μου
kai thōmas apokrinomai kai eipon autos mou kyrios kai mou theos
and Thomas answered and said to him, my lord and my God!
Thomas addresses Jesus as ho theos, which unambiguously means the God, the One True God, God in the absolute sense.
He also says ho kyrios, again with the honorific article, which is the Septuagint rendering of the Hebrew Adonai, the preferred textual circumlocution for God's unutterable name.
Some scholars hold that this was the original ending of the Gospel, as it reaches a natural conclusion at this point. The last chapter then is a later addition, a kind of theological postscript that ties in with the theological prologue.
The point being, if John is uncertain or expressing any uncertainty in 1:1, then that is entirely and unequivocally resolved in 20:28.