I John 5:7

The King James Version contains an additional verse between this verse and the following verse in John’s epistle. This added verse in the KJV was not present in the original Greek manuscripts of the New Testament, as the following commentary explains: “Between vv 7 and 8…six Greek MSS [MSS is an abbreviation for manuscripts]…introduce a gloss [an addition to the text not found in other manuscripts] which the AV [KJV] translates as, ‘in heaven, the Father, the Word, and the Holy Ghost: and these three are one.’ “The earliest of these Greek witnesses, all of which depend on an earlier Latin tradition, can be dated to the twelfth century. The OL [Old Latin] is the only ancient version to include the words, and then with variations between the MSS; but, although the evidence is not entirely clear, the passage seems to be unknown in these texts before the eighth century. It does not appear in Jerome’s definitive edition of the Vg [the Latin Vulgate] (circa A.D. 404), even if some other MSS of the Vg contain the addition. The earliest extrabiblical writer to show knowledge of the section is the Spanish heretic Priscillian (who died circa A.D. 385), when quoting from this part of John in his Latin ‘Book of Apology’ (Liber Apologeticus). None of the Greek Fathers quote the words. Despite this slight MSS attestation the inclusion remained in the Vg. and also survived in the AV [KJV]. In most modern translations the words have disappeared from the text altogether. “The section, which in any case interrupts the thought of the passage, is clearly an interpolation [an addition to the original text]. Presumably it represents an attempt on the part of those who, in the third and fourth centuries, were preoccupied with understanding the doctrine of the Trinity, to explain this text in a trinitarian manner. What may have begun…as a marginal gloss [a notation in the margin of the text] in a Latin MSS then became incorporated in the text, and was eventually translated back into the Greek in some Greek MSS” (Word Biblical Commentary, Vol. 51, p. 273, Word Book Publishers, Waco, Texas, 1984).