In Greek New Testament and others the first words of this verse are taken as forming verse 7. Between there are three witnesses and the Spirit, the water, and the blood, the Textus Receptus inserts “in heaven, the Father, the Word, and the Holy Ghost; and these three are one. And there are three witnesses on earth.” The first part of this insertion does not fit the context, for the congregation does not need a group of witnesses in heaven. And when this part is omitted, the second part becomes unnecessary: there is no need then to state expressly that the other group of witnesses is on earth.

This objection agrees with the textual fact that the words in question are not found in a single one of the old Greek manuscripts. They occur only in some Latin versions and have been adopted in the Vulgate (although they were not in the oldest manuscripts of that version). Consequently the insertion is not included in any modern edition of the Greek text nor in most modern versions.

It is much to be preferred that a translator follow this example. Sensitivities among the people who will use his translation, however, may compel him to include the inserted words. In such a case he should place them either in square brackets in the text (as done, for example, in Nieuwe Vertaling) or in a footnote (Bible de Jérusalem), preferably the latter.

In the Greek the verse begins with a connective that is often rendered by ‘for.’ Here, however, it serves to introduce a further statement of what precedes rather than the reason for it. Therefore it may be rendered ‘(yes,) actually.’ Some versions omit it altogether (among them Revised Standard Version, Good News Translation), which is quite acceptable in a case like this.

There are three witnesses, the Spirit, the water, and the blood: the Greek sentence is grammatically inconsistent in that witnesses (literally “witnessing-ones”) is of the masculine gender, although the three nouns in apposition to it are neuter. In the case of Spirit this inconsistency is found also in John 14.26 and 15.26, where it is used to indicate that the Spirit is viewed as a person. In a similar way the two other nouns, the water and the blood, are given here personal qualities. They are said to be “witnessing,” which is basically an activity of persons.

In several receptor languages it may be possible to say that a spirit is witnessing, but not that water or blood are doing so. When that is the case one may have to use a less decidedly personal rendering of “witness,” as found in ‘three the-ones showing-true: the Spirit, …’ ‘there are three that prove it (or cause it to be known). They are: the Spirit, …’

The verb “to be” is in the present tense. This tense contrasts with the aorist which the Greek uses in “he who came by water and blood” (verse 6). Consequently the reference is no longer to events that happened at a specific moment in the past but to something that takes place in the present and will continue in the future.

This suggests that in the present passage the phrase the water and the blood refers to the sacramental elements, the water of baptism and the wine of the Lord’s Supper, which form the counterpart to Christ’s baptism and his sacrificial death. These sacraments are and will be present in the congregation as continuous witnesses to the truth of Christ’s incarnation and redemptive death. As such their function is similar to that of the Holy Spirit, who brings to remembrance all that Jesus has said, and bears witness to him (compare the above quoted passages of John’s Gospel).

If the two passages are interpreted thus, the rendering of the water and the blood here may have to differ from the one used in verse 6 for “water and blood.” Several versions, for instance, render these words without any addition in the present verse, whereas they added a more or less explicit reference to Jesus’ baptism and death in verse 6.

And these three agree, or “and the three are one” (Goodspeed), “and they all say the same thing” (Phillips), ‘these, even though three, are of one accord (literally their innermosts are in each other).’ This is an allusion to a rule of Jewish law: “a charge must be established on the evidence of two or of three witnesses” (Deut 19.15, New English Bible). Accordingly the clause intends to show that the evidence for the assertions just given is beyond any legal doubt. From this it follows that the metaphorical use of “witness” found in these verses is based on the legal sense of that term. The same holds true of “testimony” in verses 9-11.

Speaking of the testimony that God has caused the three witnesses to give (verses 6-8), the author is reminded of the testimony God himself has given about the fact that Jesus is his Son. Verses 9-12 discuss this divine testimony which is the foundation of the testimony of the earthly witnesses.

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 .