Passage

1 John 5.7

Book: 1 John · NASB95

Verse

"For there are three that testify:" (1 John 5:7, NASB95)

(The next verse identifies the three; vv. 7 and 8 form a single sentence in the critical text.)

Immediate context (±2 verses)

"This is the One who came by water and blood, Jesus Christ; not with the water only, but with the water and with the blood. It is the Spirit who testifies, because the Spirit is the truth... the Spirit and the water and the blood; and the three are in agreement." (1 John 5:6, 8, NASB95)

Setting

Speaker: John the Apostle, in his pastoral epistle defending the apostolic-eyewitness gospel against early proto-gnostic / Cerinthian teachers who divorced "the Christ" from the historical Jesus.
Audience: Late-first-century Christian communities in the Roman province of Asia (greater Ephesus).
Location: Traditionally Ephesus.
Time period: c. AD 85-95.

Theological reading

The verse is the locus of Christianity's most famous textual-critical case, the Comma Johanneum, and must be handled with that issue named directly.

The textual question (the Comma Johanneum)

Two readings of 1 John 5:7-8 circulate:

Critical text (NA28, UBS5; followed by NASB95, ESV, NIV, CSB, RSV): "For there are three that testify: the Spirit and the water and the blood; and the three are in agreement."
Textus Receptus (followed by KJV, NKJV): "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, the Spirit, and the water, and the blood: and these three agree in one."

The longer reading, the Comma Johanneum (Latin "the Johannine clause"), names the three as Father, Word, and Holy Spirit explicitly, and is therefore an apparent proof-text for the Trinity. The textual-critical evidence is unfortunately decisive against its authenticity:

Greek manuscript evidence. The Comma is absent from every Greek manuscript before the 14th century. It appears in only four late, atypical Greek manuscripts (61, 629, 918, 2473), and in the margins of four others as a later correction. By contrast, the shorter reading is present in every major early uncial, Sinaiticus (ℵ, 4th c.), Vaticanus (B, 4th c.), Alexandrinus (A, 5th c.), and in the entire Greek tradition until the 14th century.
Patristic evidence. No Greek Father cites the Comma in any extant work, including those engaged in the most intense Trinitarian polemics. Athanasius (against the Arians), Basil, Gregory of Nazianzus, Gregory of Nyssa, John Chrysostom, Cyril of Alexandria, none. The Comma would have been their decisive proof-text against Arius if they had had it. Their silence is loud.
Latin evidence. The Comma originates in Latin tradition, appearing first in the 4th-century treatise Liber Apologeticus (attributed to Priscillian, d. AD 385) and subsequently in some Old Latin manuscripts and in the Vulgate (where it migrated from a marginal gloss into the text by the 9th century).
The Erasmus story. Erasmus omitted the Comma from his 1516 Greek New Testament (the basis for the eventual Textus Receptus). When attacked, he reportedly promised to include it if a single Greek manuscript could be produced. Manuscript Codex Montfortianus (61), produced specifically to meet his challenge, c. 1520, by an Oxford Franciscan, was duly produced; Erasmus included the Comma in his 1522 edition under protest, suspecting the manuscript was forged for the occasion (it was). The KJV (1611) inherited the reading from this lineage.

Modern critical editions, including evangelical and Catholic ones (NA28, UBS5, Editio Critica Maior), reject the Comma. The Trinitarian apologetic does not need it, and gains credibility by acknowledging the textual fact.

What the verse actually says (and why it still matters)

In the critical text, vv. 6-8 present a threefold testimony to the identity of Christ: the Spirit, the water, and the blood. Three readings of the imagery have currency:

Sacramental: the Spirit (Pentecost), water (baptism), blood (Eucharist), the ongoing means by which Christ's identity is testified to in the church.
Christological-historical: the Spirit (descending at Christ's baptism), the water (His baptism by John), the blood (His passion), bookends of His ministry; against Cerinthus's claim that "the Christ" descended on Jesus only between baptism and crucifixion, John insists Christ came by water AND blood, not by water only.
Forensic: drawing on Deuteronomy 19:15's "two or three witnesses" rule, the three testimonies establish Christ's identity by Mosaic-legal standard.

The threefold structure is implicitly Trinitarian even without the Comma. The Spirit testifies; the historical Jesus (water of baptism, blood of cross) is the testified-to; the Father is the one who sent Spirit and Son and to whom the testimony orders the believer. The Comma makes this Trinitarian shape explicit; the shorter text leaves it implicit but no less real.

Why this matters apologetically

Against KJV-onlyism / TR-defense: the textual evidence is overwhelming and known. Christian honesty about the Comma's spuriousness is itself an apologetic, it shows that Trinitarian doctrine does not rest on this verse, and that Christianity is willing to follow evidence even when it costs a beloved proof-text.
Against oneness Pentecostal / modalist critique: modalists sometimes weaponize the Comma's weakness ("see, you Trinitarians had to fabricate a verse!"). The actual response is that no historic Trinitarian creed or council (Nicaea, Constantinople, Chalcedon) cites 1 John 5:7, they were all written before the Comma existed in the Latin West. The doctrine of the Trinity was settled on John 1, John 14-16, Matthew 28:19, the baptismal narratives, and the broader apostolic witness; the Comma added nothing essential.
Against atheist textual-criticism polemics (Bart Ehrman in Misquoting Jesus uses the Comma as exhibit A): the Comma is exactly the kind of textual variant that critical scholarship catches and removes, far from showing Christianity is built on textual corruption, it shows the textual-critical apparatus works. The doctrine survives the discipline.

Key words (Greek)

testify, μαρτυροῦντες / martyrountes, present active participle of martyreō (G3140): legal-witness verb. The same root produces martyr (one who testifies with their life). The verb is used 33 times in 1 John alone, testimony is the epistle's central category.
Spirit, πνεῦμα / pneuma (G4151): the Holy Spirit; the same noun as in John 14-16. See G4151 - pneuma when built.
water, ὕδωρ / hydōr (G5204): in Johannine usage points to baptism (John 3:5) and to the side-piercing (John 19:34, "blood and water came out").
blood, αἷμα / haima (G0129): in Johannine usage, the cross/passion blood; also the eucharistic cup (John 6:53-56) and the side-piercing (John 19:34). The pairing of water and blood echoes John 19:34 specifically.
agreement / one, εἰς τὸ ἕν / eis to hen (literally "into the one") in v. 8: not numerical identity (against modalism) but agreement, convergence, three witnesses, one verdict. Cf. John 17:21 ("that they may be one, even as We are one") for the same structure of plural-distinct-yet-unified witness.

Cross-references

1 John 5.6, the immediately preceding verse; "came by water and blood, not with water only", the anti-Cerinthian set-up
1 John 5.8, the inseparable continuation; identifies the three witnesses
John 19.34, water and blood from the pierced side of Christ; the historical anchor for the imagery
John 14.26, the Spirit will testify of Christ; cf. John 15.26
John 5.31-39, Christ's "I have a greater witness than John" speech; the multi-witness pattern
Matthew 28.19, Trinitarian baptismal formula (the doctrinally load-bearing Trinity-text the Comma was not needed for)
Deuteronomy 19.15, "two or three witnesses" Mosaic legal rule that John is invoking