In this (see comments on “by this” in 2.3) points forward to the that clause, as in 3.16. Using a more ordinary clause order, one might say ‘God sent his only Son into the world, so that…; by doing so his love was made manifest (or he did so to make manifest his love).’

The love of God was made manifest among us: for the construction love of God, see comments on 2.5. In the present verse God is to be taken as the agent of loving. At the same time he is the implied agent of was made manifest. Accordingly one may have to shift to such renderings as ‘the love God has was made manifest among us,’ ‘God showed us that he loves.’ For was made manifest see comments on 1.2c.

However, the prepositional phrase among us (literally “in us”) can also mean “towards/for us”; it can be taken with the verb (as in Revised Standard Version) or with the noun. In the latter case the clause is to be rendered ‘the love of God towards us became manifest,’ or “God showed his love for us” (Good News Translation), ‘God made clearly visible that he loves us.’ This second interpretation seems to be more probable. It is supported by verse 16, “the love God has for us,” where the Greek uses the same preposition as in the present verse.

Verse 9b, he sent his only Son … life through him, probably quotes a standing phrase, well known to John and his readers as part of the Christian tradition (compare John 3.16).

God sent: since God has been mentioned in verse 9a, a pronoun would have been sufficient here. The use of the full designation is probably due to the fact that it occurred in the fixed wording of a traditional formula. The Greek has the perfect tense, which is in accordance with the fact that the next clause mentions the lasting effect of God’s sending Jesus.

“To send into” is sometimes to be rendered more analytically; for example, ‘to order a person to go into,’ ‘to say to a person, “Go into…” ’; compare also A Translator’s Handbook on the Gospel of Luke on 1.19. The implication is here that the person who is sent out will return after a period in which he has to perform a task.

His only Son: the term only Son occurs also in John 1.14, 18; 3.16, 18. It is used with reference to the unique relationship existing between God and Jesus, and serves to stress that God could reveal his love for man only through Jesus. For his Son see comments on 1.3.

For only the Greek has here a compound word formed by the components “only/alone” and “race/stock/class/kind,” and meaning “the only one of its class/kind.” Used in connection with “son” or “child,” the word says that there are no other sons or children.

Some interpreters suppose that the meaning of the word in question has also been influenced by a Greek verb that is related to its second component and has the meaning “to beget,” “to cause to be born.” If that is true the term may have the connotation of “only-begotten,” or “begotten of the Only One.”

However that may be, the translator can best use the term which in the receptor language is the common designation for an only child, that is, a child that does not have brothers and/or sisters. In several languages one can use a term like ‘sole,’ ‘unique.’ In others a descriptive phrase must be used, sometimes in a different syntactic position; for example, ‘his-own-son who-was one,’ ‘his son, only one like that,’ ‘God sent his Son…. God has only one Son (or has no other Son).’

For the world see comments on 2.15, meaning (2).

So that we might live through him: the Greek conjunction used may indicate aim (hence “in order that”) or expected result (hence “so that”); both meanings are possible here, and the former is slightly more probable. In some cases the governing verb “he sent” has to be repeated before this clause.

The ultimate cause or initiator of the process is God, who is the subject of the preceding sentence. The intermediary or direct cause, indicated by “through (the agency of) him,” is “the only Son.” The grammatical subject of the clause, we, is, semantically speaking, the recipient rather than the agent. Therefore it is often preferable to change the clause structure, for example; ‘in order that he/God causes us to live through his Son (or by what his Son did),’ ‘to let us have (or to grant us) life through him’ (compare Goodspeed, Bijbel in Gewone Taal), or, not making explicit the ultimate cause, ‘in order that his Son might give us life,’ “to bring us life” (New English Bible).

For “to live” or ‘to have the true life,’ see comments on 1.1. In meaning the verb is virtually identical with “to have eternal life,” as the parallel verse John 3.16 shows.

Quoted with permission from Haas, C., de Jonge, M. and Swellengrebel, J.L. A Handbook on The First Letter of John. (UBS Handbook Series). New York: UBS, 1972. For this and other handbooks for translators see here .