Much of the KJV New Testament relies on the Textus Receptus, a collection of late and sometimes corrupted Greek manuscripts, leading to inclusion of later additions such as the Johannine Comma (1 John 5:7-8), which appears in the KJV but is absent from the earliest Greek manuscripts and is regarded as a non-original Trinitarian affirmation.

Concede this fully and directly, without hedging. The Comma Johanneum ('For there are three that bear record in heaven, the Father, the Word, and the Holy Ghost: and these three are one...') is universally recognized by textual critics — including conservative and evangelical scholars, not only critical ones — as a later Latin addition. It is absent from every Greek manuscript before roughly the 14th-16th centuries, absent from the earliest and best uncials (Sinaiticus, Vaticanus, Alexandrinus), absent from the earliest versions (Old Latin, early Vulgate, Syriac, Coptic), and conspicuously absent from every patristic citation of 1 John during the 3rd-4th century Trinitarian and Arian controversies, where it would have been a decisive proof-text had it been known. It arose as a marginal theological gloss in the Latin tradition that was eventually absorbed into the text of some Latin manuscripts, then backformed into a handful of very late Greek minuscules under Vulgate influence. Erasmus initially omitted it from his Greek NT on sound textual grounds and included it only in his third edition (1522) under pressure, after being presented with a late manuscript (Codex Montfortianus) that appears to have been produced specifically to force the issue. Bruce Metzger's A Textual Commentary on the Greek New Testament gives the standard critical treatment, rating the case for exclusion at the highest degree of certainty. Virtually every modern critical Greek text (Nestle-Aland, UBS) and modern translation (NRSVUE, NIV, ESV, NASB) omits it from the main text or relegates it to a footnote.

Trinitarian doctrine does not depend on this verse in the slightest. It rests on the cumulative weight of the NT's own Christology and triadic language: the single shared 'name' of Father, Son, and Holy Spirit in the baptismal formula (Matt 28:19), the deity and pre-existence of the Word (John 1:1), Jesus's claim of unity with the Father (John 10:30), Thomas's confession 'My Lord and my God' (John 20:28), and the fully triadic benediction (2 Cor 13:14) — texts worked out doctrinally at Nicaea (325) and Constantinople (381), centuries before the Comma appears anywhere in the Greek manuscript tradition. That mainstream, overwhelmingly Trinitarian textual scholarship has itself identified and removed a verse convenient to its own theology, with no plausible motive except fidelity to the evidence, demonstrates the discipline's integrity rather than its unreliability.