All you have to do is go back to the earliest source you can find in the original language.
Taking you at your word that the earliest source is the only one to be trusted, let's take a look at a couple. You can translate them for yourself to determine if modern Greek scholarship has properly translated the ancient Greek.
P66 dates of c.175 or c.125-150 A.D. (John 1:1-6:11, 6:35b-14:26,29-30; 15:2-26; 16:2-4; 16:6-7; 16:10-20:20; 20:22-23; 20:25-21:9; 21:12,17 (fragments of John 19:16). John 1:1 reads:
Ἐν ἀρχῇ ἦν ὁ λόγος, καὶ ὁ λόγος ἦν πρὸς τὸν θεόν, καὶ θεὸς ἦν ὁ λόγος.
P75 175-200 A.D., or 175-225 A.D. (most of Luke and John. John 1:1-11:45; 11:48-57; 12:3-13:1; 13:8-9; 14:8-15; part of 14:16; 14:17-29; 15:7-8). John 1:1 reads:
Ἐν ἀρχῇ ἦν ὁ λόγος, καὶ ὁ λόγος ἦν πρὸς τὸν θεόν, καὶ θεὸς ἦν ὁ λόγος.
Both P66 and P75 in English read: In beginning was the Word, and the Word was with the God, and God was the Word.
For John 1:18 P66 reads:
μονογενὴς θεός. P75 reads:
ὁ μονογενὴς θεός. monogenēs theos. P75 with the definite article. In English the "only begotten God".
Again P66 contains John 20:28
ἀπεκρίθη Θωμᾶς καὶ εἶπεν αὐτῷ· ὁ κύριός μου καὶ ὁ θεός μου In English read: And Thomas answered and said to him, The Lord of me and the God of me.
[
Revelation 19:13 The earliest Codices are Sinaiticus (340-350 A.D.) and Alexandrinus (c.450 A.D) have all of Revelation.
η μη αυτοϲ και πε ριβεβλημενοϲ ϊ ματιον περιρεραμ μενον αιματι και κεκλη το ονομα αυτου ο λογοϲ το
In English: He is dressed in a robe dyed by dipping in blood, and the title by which He is called is The Word of God.
Daniel B. Wallace is Senior Professor of New Testament Studies at Dallas Theological Seminary (has taught there for more than 28 years) and Executive Director of the Center for the Study of New Testament Manuscripts. (CSNTM) He earned a B.A. at Biola University (1975) with a major in biblical studies and minor in Greek; graduated
magna cum laude from Dallas Seminary with a ThM degree (1979), with the equivalent of a major in Old Testament studies and a double major in New Testament Studies; graduated
summa cum laude from Dallas Seminary with a PhD in New Testament studies (1995). He has done postdoctoral study at Tyndale House, Christ’s College, Clare College, and Westminster College, Cambridge; the Institut für neutestamentliche Textforschung (Institute for New Testament Textual Research), Münster, Germany, Tübingen University; Glasgow University; Bayerische Staatsbibliothek (Bavarian State Library), Munich; as well as various libraries and monasteries in Europe, Australia, America, and Africa.
As an internationally known Greek New Testament scholar, Wallace has been a consultant for four Bible translations—ESV, TNIV, New King James Bible, and New English Translation. He has also contributed articles to the ESV Study Bible and the Holman Christian Standard Study Bible.
He states: "No textual debates on John 1.1c exist in any standard work on Jesus-θεός passages, until fourteen years ago. NT textual critics were unanimous in their certainty of John 1:1c. This scholarly agreement continues today even though one textual critic, Bart Ehrman, stated his reluctance to dismiss a single eighth-century Alexandrian manuscript, L."
"Although the most probable understanding of the anarthrous θεός is qualitative (the Word has the same
nature as God),
36 three points concern us here textually. First, both P75 and Codex B attest to the absence of the article in
37 Kenneth W. Clark concludes, “it is our judgment that P75 appears to have the best textual character in the third century.”
38 Likewise, Ehrman concurs, “[a]mong all the witnesses, P75 is generally understood to be the strongest.”
39 Thus, this evidence significantly strengthens our initial external examination in favor of an anarthrous θεός."...
“The term θεός appears in some form 83 times. Of these 63 are articular and 20 anarthrous. Still, it is highly improbable that the Fourth Evangelist intends any consistent distinction to be drawn between θεός and ὁ θεός.”
At any rate, the scholarly consensus is correct, then, that the
text is certain and every viable MS ascribes the title θεός to Jesus. For that reason, I will press on to John 1.18...
Θεός is attested in the best Alexandrian majuscule (B) and in the earliest available MSS (P66 P75).
61 The significance of this is that if the Alexandrian witnesses for υἱός (e.g., T Δ Ψ 892 1241) cannot reasonably go back to the Alexandrian archetype its attestation therein is almost a moot point...
What impresses us here, though, is that θεός is attested again outside the Alexandrian tradition (e.g., the Pe****ta [syrp] in the Gospels is close to the Byzantine type of text and was “transmitted with remarkable fidelity” and syrh(mg) is close to the “Western” type of text).
73 At the same time, θεός is the exclusive reading in both the Arabic and Coptic traditions.
74 θεός, then, is also attested in one of the earliest versions of the NT where υἱός is completely absent (the Coptic versions)...
The real question would then become, “How early?” To answer this objection, the evidence reveals that earlier MSS (in fact, the earliest) attest to θεός (and well before the Arian controversy). This indicates that the objection would remain highly speculative and against the clearer testimony of earlier and better MSS. In other words, the
earliest and
best MSS heighten the argument away from the allegation that this is an orthodox corruption (as well as the fact that both sides of this Christological controversy use/quote θεός).
Regarding Heb.1:8 He states: In the end, I believe that the preponderance of evidence (geographically, genealogically, and internally) points to the true textual reading, “but to the Son [he declares], ‘
Your throne, O God, is forever
and ever, and a righteous scepter is the scepter of
your kingdom.’ ” The probability, then, is high that Heb 1.8 explicitly calls Jesus θεός.
Regarding 2 Peter 1:1 ἐν δικαιοσύνῃ τοῦ
θεοῦ ἡμῶν καὶ σωτῆρος Ἰησοῦ Χριστοῦ In English read: Simon Peter, an Apostle and servant of Jesus Christ, to those who have received a faith that through the justice of our God and Savior Jesus Christ is of equal privilege as is ours; Dr. Wallace states:The external support, however, overwhelmingly favors of θεοῦ. In fact, the NA27 and
Editio Critica Maior together only list nine witnesses for κυρίου (mentioned above, with only the NA27 listing vgmss). This means virtually all other witnesses support θεοῦ...the Granville Sharp Rule undoubtedly applies to this construction, thereby referring both titles (“God” and “Savior”) to Jesus Christ. “It is hardly open for anyone to translate 1 Peter 1:3 ‘the God and Father’ and yet here decline to translate ‘the God and Saviour’.
As a matter of fact, although Ehrman did not mention Titus 2.13 specifically in
Orthodox Corruption, by his own argument regarding 2 Pet 1.1, Titus 2.13 would explicitly equate Jesus with θεός, “Because the article is not repeated before Ἰησοῦ (in 2 Pet 1:1), it would be natural to understand both ‘our God’ and ‘Savior’ in reference to Jesus [our ‘God and Savior’]” (
Orthodox Corruption, 267). In other words, Ehrman recognizes that one article with two nouns joined by καί refers to the same person; making Titus 2.13 an
explicit reference to Jesus as θεός.
The deity of Christ is not jeopardized even if υἱός is original. Although that shouldn’t be a factor in the discipline of textual criticism, this does allow certain (evangelical?) textual critics to follow the evidence to a relatively objective conclusion. On the other hand, Ehrman does have a tremendous problem if θεός ends up being the best reading because it would contradict his overall thesis and would put a major dent in his
a priori assumption that Jesus is not called θεός in the NT. For example, Ehrman specifically states that if μονογενὴς θεός is the original text in John 1.18 then “the complete deity of Christ is affirmed” (Ehrman,
Orthodox Corruption, 78). Yet this is a theological belief he does not support at this time.
It was not a doctrinal innovation to combat Arianism in the third century. Nor was it a sub-apostolic distortion of the apostolic kerygma in the second century. Rather, the church’s confession of Christ as θεός began in the first century with the apostles themselves and/or their closest followers and therefore most likely from Jesus himself.
Even if the early Church had never applied the title θεός to Jesus, his deity would still be apparent in his being the object of human and angelic worship and of saving faith; the exerciser of exclusively divine functions such as creatorial agency, the forgiveness of sins, and the final judgment; the addressee in petitionary prayer; the possessor of all divine attributes; the bearer of numerous titles used of Yahweh in the OT; and the co-author of divine blessing. Faith in the deity of Christ does not rest on the evidence or validity of a series of ‘proof-texts’ in which Jesus may receive the title θεός but on the general testimony of the NT corroborated at the bar of personal experience."
Jesus as Θεός (God): A Textual Examination
Finally even Bart Ehrman must conclude: "For John, Jesus was a pre-existent divine being – the Word of God who was both with God and was God at the beginning of all things – who became a human."
https://ehrmanblog.org/jesus-as-god-in-the-synoptics-for-members/
Will you still accept the earliest manuscript evidence as your final authority?
