In Part 3 of this series, we examined Ahmed Deedat’s primary arguments for identifying Muhammad as the “Comforter” promised in John 14–16. We found that both the Periklytos conspiracy theory and the descriptive arguments failed under scrutiny.
But Deedat makes one more move that deserves separate treatment. He appeals to what he calls a biblical “Litmus Test” for identifying true prophets—a test he claims Muhammad passes with flying colors.
The passage is 1 John 4:1–2:
“Beloved, believe not every spirit, but try the spirits whether they are of God: because many false prophets are gone out into the world. Hereby know ye the Spirit of God: Every spirit that confesseth that Jesus Christ is come in the flesh is of God.”
Deedat’s argument is straightforward: Islam teaches that Jesus was a real human being—the Messiah, born of Mary, who walked the earth in flesh and blood. Muhammad confessed this. Therefore, Muhammad passes the test. The “Spirit” that inspired him was the Spirit of God.
It sounds simple. But the argument depends on several moves that cannot withstand examination.
The Spirit-Prophet Equation
Deedat’s first move is to establish that “spirit” and “prophet” are synonymous terms. The text says to “try the spirits” because “many false prophets have gone out.” Therefore, he reasons, a “spirit” is simply a prophet—a human claimant to divine revelation. Testing the “spirits” means testing the prophets.
This conflation sounds plausible but collapses under scrutiny.
Source vs. Vessel
Biblical scholarship distinguishes between the prophet (the human mouthpiece) and the spirit (the supernatural source of inspiration). The command to “test the spirits” is not merely an instruction to evaluate human teachers but to discern the origin of their utterances—whether they proceed from the Spirit of Truth (the Holy Spirit) or the spirit of error (demonic influence).
A prophet is a vessel; a spirit is what fills the vessel. The test concerns the source, not merely the spokesperson.
The “God Is Spirit” Problem
If Deedat’s equation (spirit = prophet) held universally, it would create theological absurdity elsewhere in Scripture.
In John 4:24, Jesus declares: “God is Spirit” (Pneuma ho Theos).
If “spirit” simply means “prophet,” this verse would read: “God is a Prophet”—a proposition that degrades the Creator to the status of a creature. This is heresy in both Christianity and Islam. No Muslim would accept that Allah is merely a prophet.
Similarly, the “Holy Spirit” would become the “Holy Prophet”—yet Scripture describes the Spirit as omnipresent (Psalm 139), indwelling all believers, and proceeding from the Father. No human prophet possesses these attributes.
The equation fails. “Spirit” and “prophet” are related but not synonymous. The former refers to a supernatural reality; the latter to a human office.
What Was the Test Actually Testing?
Deedat assumes the “test” of 1 John 4:2 is simply acknowledging that Jesus existed as a biological human rather than a myth or legend. Since Islam affirms Jesus was a real man, Muhammad passes.
But this reading ignores the historical context of the epistle entirely.
The Docetic Heresy
First John was written to combat Docetism—from the Greek dokein, meaning “to seem” or “to appear.” This was an early Gnostic heresy that taught matter was inherently evil and spirit inherently good. Therefore, the Divine Son could not have actually inhabited a physical body; he only appeared to be human. Jesus was a phantom, a divine being wearing the costume of flesh without truly possessing it.
The confession that “Jesus Christ is come in the flesh” was a defense of the Incarnation—the belief that the pre-existent Divine Son permanently united with human nature. It was designed to exclude Gnostics who spiritualized Jesus away, not to validate future religious figures who denied his divinity.
What the Test Actually Demands
The test is not: “Do you believe Jesus had a physical body?”
The test is: “Do you confess that the Christ—the Divine Son—has come in flesh?”
This presupposes:
- The Christ existed before the flesh (pre-existence)
- The Christ entered into flesh (Incarnation)
- The Christ and the flesh are genuinely united (not merely apparent)
A confession that Jesus was only a man created from dust—like Adam—actually aligns with the very reductionism the epistle opposes. The Docetists denied that God truly became man; Deedat denies that Jesus truly was God. Both fail the test, from opposite directions.
The Grammar of Pre-Existence
Deedat reads “come in the flesh” as equivalent to “born as a human.” But the Greek grammar carries far heavier theological weight.
The phrase uses the perfect participle elēlythota (“has come”). This grammatical construction implies a pre-existent state from which the subject arrived. It presupposes that the “Christ” existed before the flesh and then entered into the flesh.
Consider the difference:
- “John came to the party” implies John existed before the party and traveled there.
- “John was born at the hospital” implies John’s existence began at that location.
The Greek of 1 John 4:2 matches the first pattern, not the second. It assumes the Christ pre-existed and then “came” into flesh.
Islamic Theology and Pre-Existence
Islamic theology explicitly denies the pre-existence of Jesus. According to Islamic teaching, Jesus did not exist before his conception; he was created ex nihilo (from nothing) by the divine command “Be” (Kun). Jesus, in this view, is a creature—exalted, prophetic, miraculous in his birth, but still a created being with a beginning.
Therefore, in Islamic theology, Jesus did not “come” (descend) into flesh; he was created as flesh. The grammar of the test assumes precisely what Islam denies.
Deedat cannot pass a test whose very structure presupposes a doctrine he rejects.
The Comprehensive Definition of Antichrist
Perhaps the most significant problem with Deedat’s argument is that he isolates 1 John 4:2 from its broader epistolary context. The author of 1 John does not leave us guessing about what he means. He provides explicit definitions elsewhere in the letter.
The Father and Son Criterion
In 1 John 2:22–23, the author writes:
“Who is a liar but he that denieth that Jesus is the Christ? He is antichrist, that denieth the Father and the Son. Whosoever denieth the Son, the same hath not the Father.”
Here the “Litmus Test” becomes comprehensive. To pass, one must:
- Confess the Incarnation (4:2)
- Confess the Father and the Son (2:22–23)
The second criterion is devastating to Deedat’s argument.
Islam and the Father-Son Relationship
The Qur’an and Islamic theology explicitly reject the title “Son of God” for Jesus. Surah 4:171 states: “Christ Jesus the son of Mary was no more than a messenger of Allah… Say not ‘Trinity’… Allah is One God: Glory be to Him: far exalted is He above having a son.”
To call Jesus the “Son of God” is considered shirk—the unforgivable sin of associating partners with Allah. Similarly, Islamic theology rejects the notion that God is a “Father” in any relational sense.
But 1 John 2:22 explicitly states that denying the Father and the Son is the mark of the antichrist—not the Spirit of Truth, but the spirit of error.
By the comprehensive standard of 1 John, the denial of the Father-Son relationship identifies a teaching as proceeding from the spirit of antichrist, not from God.
Deedat’s Dilemma
Deedat cannot have it both ways. He cannot cite 1 John 4:2 as his “Litmus Test” while ignoring 1 John 2:22, which is part of the same letter, written by the same author, addressing the same issues.
If 1 John 4:2 is authoritative for testing prophets, then 1 John 2:22 is equally authoritative. And by that standard, any teaching that denies Jesus is the Son—which Islam explicitly does—fails the test.
What Does Islam Actually Confess?
Let us be precise about what Islamic theology affirms regarding Jesus:
- Jesus was a human prophet, born of the Virgin Mary
- Jesus performed miracles by Allah’s permission
- Jesus was the Messiah (al-Masih)
- Jesus was not divine
- Jesus was not the Son of God
- Jesus did not die on the cross (most Islamic interpretations)
- Jesus did not pre-exist his conception
Deedat emphasizes the points of agreement (human, Messiah, miracles) while minimizing the points of disagreement (divinity, sonship, pre-existence, crucifixion).
But 1 John’s test is not a partial-credit examination. The epistle was written precisely to distinguish authentic Christian confession from teachings that used some Christian vocabulary while denying its substance.
The Docetists also affirmed that “Jesus Christ” was real—they simply denied he had genuine flesh. The test excluded them. Islam affirms Jesus had genuine flesh—but denies he was the divine Son. The test excludes this as well.
The Test in Full
When we read 1 John holistically rather than cherry-picking verses, the “Litmus Test” emerges as follows:
A true confession affirms:
- Jesus Christ has come in the flesh (4:2) — the Incarnation of a pre-existent Person
- Jesus is the Christ, the Son of the Father (2:22–23) — divine sonship
- The Father and Son are to be confessed together (2:23) — Trinitarian relationship
A false confession denies:
- The genuine humanity of Christ (Docetism)
- The genuine divinity of Christ (Arianism, Islam)
- The Father-Son relationship (Islam)
Deedat’s argument requires accepting half the test while rejecting the other half. But the epistle does not permit this. The same author who wrote 4:2 wrote 2:22. Both are criteria for the same test.
Conclusion: Selective Reading Cannot Pass the Test
Deedat’s appeal to 1 John 4 as a “Litmus Test” for validating Muhammad fails at multiple levels:
Lexically, he conflates “spirit” and “prophet” in ways that create absurdity elsewhere in Scripture (“God is a Prophet”).
Historically, he ignores that the test was designed to combat Docetism—a heresy that denied the Incarnation—not to validate future teachers who deny Christ’s divinity.
Grammatically, the Greek implies pre-existence (“has come in flesh”), which Islamic theology explicitly denies.
Contextually, he isolates 4:2 from 2:22, which defines antichrist as one who “denies the Father and the Son”—a denial Islam makes explicitly and emphatically.
The “Litmus Test” of 1 John, read in full, does not validate Islam. It excludes it—not by arbitrary Christian prejudice, but by the epistle’s own stated criteria.
This is not triumphalism. It is simply reading the text that Deedat himself cited, in its entirety rather than in fragments.
Next in this series: Part 4: What Does “Guiding Into All Truth” Mean? — examining Deedat’s claim that Muhammad fulfilled the promise of practical guidance where the Holy Spirit failed.