"The translation of the Greek word "monogenes" describes the Sonshipthat Christ has with His Father. This unique relationship Jesus has with His Father can reveal some powerful things to us. Can He be either "only-begotten Son" (KJV) or the "only Son" (NIV) of the Father?
Due to an unfortunate, although well intended, set of circumstances this crucial term has come to us in many of our translations in a form that suggests that the Son of God was actually begotten, that is, that he had a beginning. The Old Latin versions correctly translated monogenes as unicus (only), and so did Jerome (A.D. 347-419) where it was not applied to Jesus. But when referring to Jesus, Jerome appears to have been influenced by the Orations of Gregory of Nazianzus1 (A.D. 329-390) who, in discussing the eternal relation between the Father and the Son, spoke of the Father as gennetor "begetter" and the Son as gennema "begotten." To answer the Arian claims that Jesus was not begotten, but made, Jerome translated it as unigenitus (only begotten), in these passages that were referring to Jesus Christ. The influence of Jeromes Vulgate on the King
James Version made "only begotten" the standard English rendition." Italics mine

Reply: This is a common explanation, but not a great one. It does not explain that even the apologetic Hilary of Poitiers (ca. 315-367 CE) in his De Trinitate, also uses the term unigenitus
when quoting John 1:14, 18 from the Old Latin. Now look at the words in italics. Did Jerome apply unicus to Jesus or not. When we read the following sentence we find that he didn't, but that is not what the preceeding sentence says. In fact, by an large, the early Christian writers would refer to Christ as "only-begotten" and the Father always as "unbegotten" (see Dialogue with Trypho, ANF 1, 263). Justin Martyr was quite adamant about this when he wrote, "God begat before all creatures a Beginning, who was a certain rational power proceeding from Himself, who is called by the Holy Spirit, now the Glory of the Lord, now the Son, again Wisdom, again Angel, then God, and then Lord, and Logos;...For He can be called by those names, since He ministers to the Father's will, and since He was begotten of the Father by an act of will."

"Although the English words of "only-Begotten" are found only six times in the New Testament, the Greek word (monogenes) appears nine times, and more often in the Septuagint. It is used literally of an only child: "the only son of his mother" (Lk 7:12); "an only daughter" (Lk 8:42); "mine only child" (Lk 9:38); "Isaac .... his only begotten" (Heb 11:17). In all other places in the
New Testament it refers to Jesus Christ as "the only begotten Son of God" (Jn 1:14,18; 3:16,18; 1 Jn 4:9). In these passages, it might be translated as "the only son of God"; for the emphasis seems to be on His uniqueness, rather than on His sonship, although both ideas are certainly present. But how do modern Biblical scholars translate this word? According to Moulton and Milligan’s Vocabulary of the Greek Testament: "monogenos is literally ‘one of a kind,’ ‘only,’ ‘unique’ (unicus), not ‘only-begotten,’ which would be monogennetos (unigenitus). Moulton and Milligan’s are telling us that the Greek word "monogennetos" meaning "only-Begotten" is not found anywhere in the Greek New Testament. So what are the New Testament writers trying to convey by the use of the correct word monogenos?"

Reply: The reason that monogennetos is not used by the Christian Bible writers or the ANF (Ante-Nicene Fathers-with the common exception to Ignateous) is that it was usually a derogatory term used to denote frailty and weakness (see Thayers and Vines 1084). Such a term would show a lack of respect for the Son of God.

The first part of this Greek word monogenes is mono which means "only," the second half of the word is from an adjectival form derived from genos, which means "origin, race, stock," so the two words put together mean "one of a kind." One of the
main arguments is that the -genes suffix is related to the verb ginomai rather than gennao, thus acquiring the meaning "category" or "genus" (category of biological classification) instead of "to beget." The word emphasizes the unique relationship that the Father has to the Son. It does not suggest the idea of begotten by one alone, by one father with-out the assistance of a mother, suggesting the doctrine of eternal generation. Instead it suggest the unique position to the Father and thus His unique ability to reveal the Father.

Reply: I agree with the above to an extent. "Unique" is a better translation than most, but it never quite explains how he the subject is unique. In the N.T., monogenes is used in a filial way, one that is used for offspring...see Thayers Greek Lexicon & BAGD. In fact the BAGD states that it could be analagous to prototokos (firstborn). In view of the above evidence, John V. Dahms in his The Johannine Use Of Monogenes Reconsidered NTS 29, 1983, p.231 states: We have examined all of the evidence which has come to our attention concerning the meaning of monogenes in the Johannine writings and have found the majority view of modern scholarship has very little to support it. On the other hand, the external evidence, especially that from Philo, Justin and Tertullian, and the internal evidence from the context of its occurences, makes clear that 'only begotten' is the most accurate translation after all."