Trinitarian scholars now admit this verse was not written by the hand of John. Having access to collections of hundreds of manuscripts, modern scholars are able to determine this verse was introduced into the Bible long after John wrote this letter. However, there are still Trinitarians, especially KJV Onlyists, who are unwilling to accept the facts on this matter and claim this verse is authentic.
Examination of the Claim
1. Trinity prooftext? What?
Trinitarians of all stripes seem to somehow think this passage would otherwise be a powerful proof for Trinitarian doctrine. This likely happens with Trinitarians because John uses the words "three" and "one" in one breath. But would it really serve to support the Trinity? Trinitarians tend to read the passage as if John were saying, "and these three are one [God]," or "these three are one [being]" or some similar idea. As such, they imagine a preconceived idea into the passage which is not present anywhere in the context.
The text says there are three that testify, indicating the subject matter of the verse concerns a united witness between these three and there is no reason one should suppose it would imply anything else. 1 John 5:7 literally says, "and these three are one." The very next verse, concerning the Spirit and the water and the blood, literally says, "the three are unto the one" meaning these too have a common and united testimony. To be consistent, the Trinitarian advocate of 1 John 5:7 should also then conclude these three, the water, the Spirit, and the blood, are also a Trinity of one being. It is quite reckless to interpret this text as declaring the Father, Word and Holy Spirit are one God when all the verse says is the three are a united witness, one testimony. The oneness in question is a oneness of purpose and function, not a oneness of identity or ontology and substance of being. In other words, the three, the Father, the Word, and the Spirit are in one united agreement concerning their witness/testimony.
In a similar sense, Jesus prayed for this same unity of oneness between himself the Father and the church. We would not therefore assume these three are "God."
I do not pray for these only, but also for those who believe in me through their word, that they may all be one, just as you, Father, are in me, and I in you, that they also may be in us, so that the world may believe that you have sent me. The glory which thou hast given me I have given to them, that they may be one just as we are one, I in them and you in me, that they may become perfectly one. (John 17:20-23).
As we can see, Jesus prayed that he and the Father and all the disciples would be one. Shall we then suppose all these are God? Of course not. And there is not reason to do so with this passage either. Both of these passages, John 17:20-23 and 1 John 5:7, are referring to function, not substance of being. This passage simply does not suggest a Triune God even if it was valid. It simply says that there are three who testify and these three are one. It also says the Spirit, water, and blood are one in the same sense. Neither of the two groups of three are to be understood one other thing but as one unified testimony.
2. It Just Isn't There
I John 5:7, also known as, the Comma Johanneum, is found in only eight late Greek manuscripts, four of which have the words in a marginal note. These marginal glosses were added after the original copy was made. Most of these manuscripts originate from the sixteenth century and the earliest manuscript, includes the reading in a marginal note which was added sometime after the original composition. There is no sure evidence the Comma Johanneum existed in any Greek manuscript until the early sixteenth century or perhaps the fifteenth century at best. From what we do know, it seems the Comma somehow found its way into Latin manuscripts sometime in the fourth or fifth century. It does not appear in any Greek script of any kind until 1215 A.D. where we find it in a Greek translation of the Acts of the Lateran Council, a work originally written in Latin.
3. The Significance of Distinguishing between the Greek and Latin Manuscripts
The European church was essentially split into two halves. The western church spoke Latin and used Latin Bibles and the eastern church spoke Greek and used Greek Bibles. So the question of Greek versus Latin manuscripts is basically a geographical issue.
It is also important to recognize the primacy of the Greek manuscripts. The New Testament was originally written in Greek. Early Christians also primarily used the Greek Old Testament (Septuagint), not the Hebrew Old Testament, and this tradition lasted for several centuries. Christians later translated the Greek into the Latin for the Latin speaking church in the western part of the Roman Empire, including northern Africa.
Now because the Greek language is the original language, and it would create numerous translation errors for copyists to translate from Greek to Latin and then translate from Latin back into Greek, scribal copyists did not translate from the Latin back into the Greek but only translated from the original Greek into Latin. Latin copies were made from both Greek copies and already translated Latin copies. >/p>
However, Greek copies were only made from Greek copies and no translation was necessary at all. Since 1 John 5:7 does not appear in any early Greek manuscripts, it shows us the verse simply was not there but was somehow introduced into the western Latin manuscripts independently from the Greek manuscripts in circulation. We also know this because the error was first localized to Spain and North Africa and then later made its way into Italy and Gaul (France). All these locations are in the locality of the western Latin speaking church.
4. Nobody noticed?
Now here is how we can be certain that 1 John 5:7 never existed in the early church. Because of the Arian controversy in the fourth century, we know for certain the church was especially guarded concerning teachings and any Scriptural evidence they thought they had concerning the Trinity. After the end of the fourth century, these manuscripts were the canonized writings of the status quo church who fought for Trinitarian teaching and it is an unthinkable proposition to suggest the eastern Greek speaking church would have let such a passage inadvertently escape from all their Greek manuscripts spread throughout the eastern half of the Roman empire. If 1 John 5:7 had been authentic, the first omission of this verse would have created an immediate outcry and church leaders would have been looking for the culprit. Indeed, blood was spilled over far less in the fourth century. It is an absolutely ludicrous fantasy to suppose the entire eastern Greek speaking Trinitarian church could have allowed 1 John 5:7 to somehow escape from all their Bibles completely unnoticed for over a thousand years.
5. Inexplicably Silent
And here is another reason we know this passage is inauthentic. We do not find single person quoting this passage in the second to fifth century debates concerning the nature of God and Christ. If indeed 1 John 5:7 was present in the original text, it is inexplicable that no one ever brought it forward concerning the deity of Christ, especially since similar sounding passages like John 10:30 enjoyed very heavy mileage. We do not find one solitary voice appealing to it through the entire Sabellian and Arian controversies and even afterward. But we do have evidence the Comma surfaced in the late fourth century in Spain or the early fifth century near Carthage.
Now Augustine loved to promote Trinitarian dogma which had been officially made the official teaching of the church by the order of Emperor Theodosius in 380 A.D. In fact, he spent nearly twenty years writing his voluminous work "On the Trinity." He never mention this verse once. Not once, Augustine also wrote a commentary on 1 John. It is ridiculous to think Augustine would have written such a huge work but somehow knew about this verse yet never mentioned it in his substantially large writings on the Trinity.
Augustine, who was a Latin speaking bishop in north Africa, wrote a tract on the Epistle of John in the first quarter of the fifth century, which shows he had never heard of 1 John 5:7. And here is what he wrote concerning the fifth chapter of John's letter.
I would not have you mistake that place in the epistle of John the apostle where he says, 'There are three witnesses: the Spirit, and the water, and the blood: and the three are one.'.... if we will inquire into the things signified I by these, there not unreasonably comes into our thoughts the Trinity itself, which is the one, only, true, supreme God, Father and Son and Holy Spirit, of whom it could most truly be said, "There are three witnesses, and the three are one:" so that by the term 'Spirit' we should understand God the Father to be signified; as indeed it was concerning the worshipping of Him that the Lord was speaking, when He said, "God is a Spirit:" by the term, 'blood,' the Son; because "the Word was made flesh:" and by the term 'water,' the Holy Spirit; as, when Jesus spoke of the water which He would give to them that thirst, the evangelist saith, "But this said He of the Spirit which they that believed on Him were to receive....And if in any other way this depth of mystery which we read in John's epistle can be expounded and understood agreeably with the Catholic faith, which neither confounds nor divides the Trinity, neither believes the substances diverse nor denies that the persons are three, it is on no account to be rejected" (Contra Maximinum Arianum, 22)
We can see here that Augustine wants these three, the Spirit, the water and the blood, to somehow be the Trinity. Notice how Augustine violently distorts the text. He says the Holy Spirit in the passage is not the mentioned Spirit, but the Father and rather the water is the Holy Spirit. This is supposed to be one of the church's greatest theologians? It is laughable. Indeed, he identifies the Spirit with the Father and he Father is NOT the Holy Spirit in Trinity doctrine. He resorts to similar ridiculous lengths in his commentary on John 17:3.
It is quite plain that Augustine had never heard of 1 John 5:7. He never mentions it in his commentary on 1 John but must rather try and turn the next verse into some kind of Trinitarian interpretation. But we see here already the zealousness toward the newly developed Trinitarian doctrine had prompted Augustine to mystically interpret 1 John 5:8 in a very violent manner in order to promote Trinitarianism. Augustine's interpretation also helps us see just how 1 John 5:7 was created.
7. Disinformation: Dishonest Propaganda
Unfortunately, the universal awareness of this counterfeit text has led to a mass of disinformation perpetuated by those who don't like the facts. There is an abundance of false claims and disinformation being spread concerning 1 John 5:7. Many of these claims noticeably are without documentary support and many of those who do provide documentary support do so very dishonestly. Some claim the Comma is found in "numerous" manuscripts but do not identify these manuscripts or tell you that the manuscripts in question are very late manuscripts. What these folks forget to mention is that the Comma is found in Greek manuscripts only at a very late date, or they forget to tell you the Comma was written in margin at a later date, or, they conveniently forget to inform you it is only found in Latin, not Greek manuscripts, etc. etc. It is not found in numerous Greek or Latin manuscripts. It is found in a few early Latin manuscripts dating from the fifth century and all of them just happen to have originated in the same locality. Another false claim is that several church fathers either "quoted," or "referred," to the Comma. Another false claim is to quote a church father but forget to tell you that the work they are quoting is under high suspicion of forgery and actually written by someone else at a later date and that type of thing. We simply cannot find a reliable early quotation for this verse and it appears to have likely been forged in Spain in the late fourth or early fifth century. Some of these claims are totally false and you will be hard pressed to find documentary support for most of them. Others are claims that the fathers made references to the Comma, but upon investigation and examination of these alleged quotations, one finds these claims are nothing but wishful thinking. "Stretching the truth" would be putting it mildly.
Here is a page on the Comma with more info which I work on from time to time: Comma Johanneum
Last Update: February 24, 2011