The first sentence in this verse occasions no exegetical problem, but the second sentence does present a serious textual difficulty. There are several possible readings: (1) The strongest Greek manuscript evidence supports the reading “the only God,” while one of the best single Greek manuscripts reads “only God.” The inclusion of the definite article “the” (see 1.1) appears to have been an early attempt to improve on the text. There is no way to explain how the article was later omitted, if it was in the text originally. (2) Other Greek manuscripts read the only Son. This reading is judged to be the easier, and, as such, perhaps a scribal assimilation to John 3.16,18; 1 John 4.9. It is difficult to understand why this reading was changed, if it was the original reading. (3) “God’s only Son” (so New English Bible) represents an attempt to make a composite text from the alternative possibilities. (4) Another possibility is “the only one.” This solution, while attractive, has very weak manuscript evidence in its support.

If one follows the recommendation of the UBS Committee on the Greek text and accepts the first textual possibility, literally, “the only God,” the expression can be divided into two parts: (1) “the only one”; and (2) “one who is the same as the Father.” Good News Translation accepts this choice of text and makes explicit “the only one” as the only Son, to avoid a misleading reference to Jesus Christ (of the preceding verse) as the only one who was with the Father before all time began. This reading is important, since Jesus Christ is a historical figure, the incarnation of the eternal Son (or Word).

At the Father’s side (Anchor “ever at the father’s side”; New English Bible, Jerusalem Bible “nearest to the Father’s heart”) is literally “in the bosom of the Father” (Goodspeed “who leans upon his Father’s breast”), and is simply a way of expressing the closest possible relationship between the Father and the Son. The precise force of the present tense (is) is disputed. Some assume that it has a past connotation, but it is best in English to render the verb in the present tense.

Expressions for close association often depend upon close spatial relations, for example, “is beside the Father,” “remains near the Father,” or “is constantly with the Father.” however, one may express this association in other ways, for example, “closely associates with the Father,” “always speak together,” or “there is never any difference between them.” Sometimes the relationship is expressed idiomatically, for example, “who lives in the heart of the Father” or “whom the Father embraces.”

The verb has made him known (so most translations; New American Bible “has revealed him”) etymologically means “to lead,” but that meaning is absent in New Testament usage. The Greek term in this context is related to the English derivative term exegesis, and the focus of meaning here is upon “clear revelation” or “clear explanation.” It is possible to translate it in some languages “he has clearly made God known” or “he has clearly shown to people who God is.” In other instances it may be necessary to say to people who God is. In other instances it may be necessary to say “he has caused people to know just what God is like.”

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on the Gospel of John. (UBS Handbook Series). New York: UBS, 1980. For this and other handbooks for translators see here .