Doctrinal Significance of John 1:18

John 1:18 No man hath seen God at any time; the only begotten Son, which is in the bosom of the Father, he hath declared him.

John 1:18 θεον ουδεις εωρακεν πωποτε ο μονογενης υιος ο ων εις τον κολπον του πατρος εκεινος εξηγησατο

John 1:18 Θεὸν οὐδεὶς ἑώρακεν πώποτε· μονογενὴς θεὸς ὁ ὢν εἰς τὸν κόλπον τοῦ πατρὸς ἐκεῖνος ἐξηγήσατο.

For ‘only begotten God’:  ?66, ?75, Codex Vaticanus, Codex Sinaiticus, Codex Ephraemi, and other Egyptian texts: in short, the Egyptian text. (Interestingly, Tischendorf rejects the ‘only begotten God’ reading uses ‘the only begotten Son’ in his text. )

For ‘only begotten Son’:  it is the universal reading of the Byzantine Text going back to Codex Alexandrinus, and universal reading of the Latin text

• some Byzantine Fathers like Basil, Gregory of Nyssa, and also Athanasius, cited the ‘only begotten God’ reading catachrestically (interpreting it to mean ‘the only begotten who is God’).
• It is believed that the Byzantine copyists, “as they were in the process of rolling back readings likely introduced by Eusebius of Caesarea into the Byzantine Text through the influence of Constantine, found ‘the only begotten Son’ to be the reading of their best and oldest manuscripts: and thus, the ‘only begotten Son’ reading quickly gained ascendancy and soon became the exclusive reading of the Byzantine Text.” (from unpublished work.)

Since God as God cannot be begotten, the reading “only begotten God” is heretical. Neither can the Godhead of Christ be begotten.  Only the Person of Christ is begotten.

John Burgon, Edward Hills state that the ‘only begotten God’ reading almost certainly originated with the Valentinian Gnostics, as Burgon demonstrated in his citation from the 2^nd century Gnostic work Excerpts from Theodotus.

DR. EDWARD FREER HILLS – THE KING JAMES VERSION DEFENDED (REPUBLISHED RECENTLY AS TEXT & TIME) P.110

The Only Begotten Son Versus Only Begotten God John 1:18 “No man hath seen God at any time; the only begotten Son, which is in the bosom of the Father, He hath declared Him.”

This verse exhibits the following four-fold variation:

1. The only begotten Son, Traditional Text, Latin versions, Curetonian Syriac.
2. Only begotten God, Pap 66, Aleph B C L, WH.
3. The only begotten God, Pap 75.
4. (The) only begotten, read by one Latin manuscript.

The first reading is the genuine one. The other three are plainly heretical. Burgon (1896) long ago traced these corruptions of the sacred text to their source, namely Valentinus.  Burgon pointed out that the first time John 1:18 is quoted by any of the ancients a reference is made to the doctrines of Valentinus. This quotation is found in a fragment entitled Excerpts from Theodotus, which dates from the 2nd century. R. P. Casey (1934) translates it as follows:

The verse, “in the beginning was the Logos and the Logos was with God and the Logos was God,” the Valentinians understand thus, for they say that “the beginning” is the “Only Begotten” and that he is also called God, as also in the verses which immediately follow it explains that he is God, for it says, “The Only-Begotten God who is in the bosom of the Father, he has declared him.”

This passage is very obscure, but at least it is clear that the reading favored by Valentinus was precisely that now found in Papyrus 75, the only begotten God. What could be more probable than Dean Burgon’s suggestion that Valentinus fabricated this reading by changing the only begotten Son to the only begotten God? His motive for doing so would be his apparent desire to distinguish between the Son and the Word (Logos). According to the Traditional reading, the Word mentioned in John 1:14 is identified with the only begotten Son mentioned in John 1:18. Is it not likely that Valentinus, denying such identification, sought to reinforce his denial by the easy method of altering Son to God (a change of only one letter in Greek) and using this word God in an inferior sense to refer to the Word rather than the Son? This procedure would enable him to deny that in John 1:14 the Word is identified with the Son. He could argue that in both these verses the reference is to the Word and that therefore the Word and the Son are two distinct Beings.

JOHN WILLIAM BURGON’S THE CAUSES OF CORRUPTION OF THE TRADITIONAL TEXT PG.166-168

We now reach a most remarkable instance. It will be remembered that St. John in his grand preface does not rise to the full height of his sublime argument until he reaches the eighteenth verse. He had said (ver. 14) that the ‘Word was made flesh,’ &c.; a statement which Valentinus was willing to admit. But, as we have seen, the heresiarch and his followers denied that ‘the Word’ is also ‘the Son’ of God. As if in order to bar the door against this pretence, St. John announces (ver. 18) that ‘the only begotten Son, which is in the bosom of the Father, he hath declared him’: thus establishing the identity of the Word and the Only begotten Son. What else could the Valentinians do with so plain a statement, but seek to deprave it? Accordingly, the very first time St. John i. 18 is quoted by any of the ancients, it is accompanied by the statement that the Valentinians in order to prove that the ‘only begotten’ is ‘the Beginning,’ and is ‘God,’ appeal to the words,—‘the only begotten God who is in the bosom of the Father,’ &c. Inasmuch, said they, as the Father willed to become known to the worlds, the Spirit of Gnosis produced the ‘only begotten’ ‘Gnosis,’ and therefore gave birth to ‘Gnosis,’ that is to ;the Son’: in order that by ‘the Son’ ‘the Father’ might be made known. While then that ‘only begotten Son’ abode ‘in the bosom of the Father,’ He caused that here upon earth should be seen, alluding to ver. 14, one ‘as the only begotten Son.’ In which, by the way, the reader is requested to note that the author of the Excerpta Theodoti (a production of the second century) reads St. John i. 18 as we do.

I have gone into all these strange details,—derived, let it be remembered, from documents which carry us back to the former half of the second century,—because in no other way is the singular phenomenon which attends the text of St. John i. 18 to be explained and accounted for. Sufficiently plain and easy of transmission as it is, this verse of Scripture is observed to exhibit perturbations which are even extraordinary. Irenaeus once writes ὁ [?] μονογενὴς υἱός: once, ὁ [?] μονογενὴς Θεός: once, ὁ μονογενὴς υἱὸς Θεοῦ: Clemens Alex., ὁ μονογενὴς υἱὸς Θεὸς μόνος; which must be very nearly the reading of the Codex from which the text of the Vercelli Copy of the Old Latin was derived. Eusebius four times writes 6ὁ μονογενὴς υἱός5: twice, μονογενὴς Θεός: and on one occasion gives his reader the choice of either expression, explaining why both may stand. Gregory Nyss. and Basil, though they recognize the usual reading of the place, are evidently vastly more familiar with the reading ὁ μονογενὴς Θεός: for Basil adopts the expression thrice, and Gregory nearly thirty-three times as often. This was also the reading of Cyril Alex., whose usual phrase however is ὁ μονογενὴς τοῦ Θεοῦ λόγος. Didymus has only [? cp. context] ὁ μονογενὴς Θεός, —for which he once writes ὁ μονογενὴς Θεὸς λόγος. Cyril of Jer. seems to have read ὁ μονογενὴς μόνος.

…

But the most important part of the Dean’s paper is found in his account of the origin of the expression. This inference is strongly confirmed by the employment of it in the Arian controversy. Arius reads Θεός (ap. Epiph. 73—Tischendorf), whilst his opponents read Υἱός. So Faustinus seven times (I noted him only thrice), and Victorinus Afer six (10) times in reply to the Arian Candidus. Also Athanasius and Hilary of Poictiers four times each, and Ambrose eight (add Epp. I. xxii. 5). It is curious that with this history admirers of B and א should extol their reading over the Traditional reading on the score of orthodoxy. Heresy had and still retains associations which cannot be ignored: in this instance some of the orthodox weakly played into the hands of heretics. None may read Holy Scripture just as the idea strikes them.]