1 John 5:7-8
The Comma Johanneum
Later additionNot in any Greek manuscript before the 14th century. A late Latin addition that entered the KJV via Erasmus's third edition.
What's at stake
The KJV reads: 'For there are three that bear record in heaven, the Father, the Word, and the Holy Ghost: and these three are one. And there are three that bear witness in earth...' Modern translations have only the second sentence. The italicised material is the Comma Johanneum.
The clearest New Testament proof-text for the Trinity in the entire KJV — and almost certainly not original. Absent from every Greek manuscript before the 14th century. Erasmus famously refused to include it in his Greek New Testament until pressure forced him to add it, on the basis of a single suspicious manuscript made to order. Without this verse, the Trinity is still implied across the NT but is no longer explicitly stated in any single passage.
Witnesses
Codex SinaiticusAD 330 – AD 360 (~AD 350)
OMITS
Codex VaticanusAD 300 – AD 350 (~AD 325)
OMITS
Codex AlexandrinusAD 400 – AD 440 (~AD 425)
OMITS
Codex AmiatinusAD 690 – AD 716 (~AD 700)
Latin Vulgate — does not have the Comma in its earliest form, though it crept into later Latin manuscripts