Readers who grew up with older English Bibles know John 1:14 and 3:16 with the words “only begotten”. Most modern translations say “one and only” or “only”. Open Word Bible does too. The reasons are in the records for John 1:14 and 1:18.
What the word means
The word in John 1:14 is μονογενοῦς, a form of μονογενής. It is built from the words for “only” and “kind”, not from the verb “to beget”. It means unique, one of a kind.
The clearest evidence is Hebrews 11:17, which uses the same word of Isaac. Isaac was not Abraham’s only son; Ishmael was born first. But Isaac was unique, the son of the promise. “Only begotten” came into English through the Latin unigenitus, and it suggests a meaning the Greek word does not carry.
So the Balanced level of John 1:14 reads:
The Word became flesh and made his home among us. We have seen his glory, the glory of the one and only Son from the Father, full of grace and truth.
The Greek does not actually say “Son” in this verse; it says “the one and only from the Father”. The translation supplies “Son” because “from the Father”, and John 3:16 and 18, make it clear. The Literal level shows that the word was added by putting it in brackets.
John 1:18: “Son” or “God”?
The same word appears again in verse 18, and here there is a question about the text itself. Some manuscripts read “the one and only Son”; others read “the one and only God”: μονογενὴς θεὸς.
Open Word Bible follows “God”. It has the oldest witnesses, the papyri P66 and P75 and the great codices Sinaiticus and Vaticanus, and it is the harder reading: scribes were more likely to change an unusual “God” to the familiar “Son” than the other way round. A footnote gives “Son”.
That creates a translation problem. “The only God”, standing alone, would suggest that the Father is not God. So the Balanced level supplies “Son”, as verse 14 did, and keeps both truths:
No one has ever seen God. The one and only Son, who is himself God and is close beside the Father, has made him known.
The last verb deserves a note too. It is the word from which “exegesis” comes, and it means to lead out, explain or narrate. No one has seen God, and the Son has made him known.