I John 2:21 · Bible study
1 John 2:21 Commentary: Knowing the Truth to Reject Lies
Greek · 11 what the commentators say
Meaning in one sentence
How knowing the truth equips believers to recognize and reject false teaching, based on 1 John 2:21 and its context.
Research Summary
- Meaning: John writes not because his readers lack knowledge but because they possess it; their knowledge of truth is the foundation for detecting lies.
- Key words: egrapsa (epistolary aorist, referring to this section of the letter), oidate (you know, from oida, full, intuitive knowledge), pseudos (lie, conscious falsehood).
- Main debate: Whether the Greek conjunction hoti in each occurrence means “because” or “that” affects the logic (Cambridge lists three possible readings).
- Theological theme: The sufficiency of the Spirit’s anointing to teach believers and equip them for discernment.
- Best use: Preached or taught alongside vv.18-27 to address concerns about spiritual deception and assurance in times of church conflict.
Translation Comparison
BSB Berean Standard Bible 2020
I have not written to you because you lack knowledge of the truth, but because you have it, and because no lie comes from the truth.
WEB World English Bible 2000
I have not written to you because you don’t know the truth, but because you know it, and because no lie is of the truth.
KJV King James Version 1769
I have not written unto you because ye know not the truth, but because ye know it, and that no lie is of the truth.
ASV American Standard Version 1901
I have not written unto you because ye know not the truth, but because ye know it, and because no lie is of the truth.
YLT Young's Literal Translation 1898
I did not write to you because ye have not known the truth, but because ye have known it, and because no lie is of the truth.
Darby Darby Bible 1890
I have not written to you because ye do not know the truth, but because ye know it, and that no lie is of the truth.
Douay-Rheims Douay-Rheims Bible 1899
I have not written to you as to them that know not the truth, but as to them that know it: and that no lie is of the truth.
Translations in other languages (10 available)
No os he escrito como si ignoraseis|strong="G3756, G1492" la verdad, sino como á los que la conocéis, y que ninguna mentira es de la verdad.
Eu vos escrevi, não porque não conheceis a verdade, mas sim, porque a conheceis, e porque nenhuma mentira vem da verdade.
Je vous ai écrit, non que vous ne connaissiez pas la vérité, mais parce que vous la connaissez, et parce qu’ aucun mensonge ne vient de la vérité.
Ich habe euch nicht geschrieben, als wüßtet ihr die Wahrheit nicht; sondern ihr wisset sie und wisset, daß keine Lüge aus der Wahrheit kommt.
Ik heb u niet geschreven, omdat gij de waarheid niet weet, maar omdat gij die weet, en omdat geen leugen uit de waarheid is.
Io vi ho scritto non perché non conoscete la verità, ma perché la conoscete, e perché tutto quel ch’è menzogna non ha a che fare con la verità.
Nie pisałem wam, przeto żeście prawdy nie znali, ale że ją znacie, a iż wszelkie kłamstwo nie jest z prawdy.
Я написал вам не потому, чтобы вы не знали истины, но потому, что вы знаете ее, равно как и то, что всякая ложь не от истины.
我寫 信給你們，不 是因 你們不 知道 真理，正是 因 你們知道，並且 知道沒 有虛謊 是 從 真理出來的。
I have not sent you this letter because you have no knowledge of what is true, but because you have knowledge, and because that which is false has nothing in common with that which is true.
Verse in Context
Original Language (Koine Greek)
New Testament · Koine Greek · I John 2:21
Source: STEPBible TAGNT/TEHB (CC-BY 4.0). Click or tap a morphology code to see the full parsing.
Scholars' Consensus
Commentators agree that John does not write to inform an ignorant audience but to confirm what they already know. The Greek verb egrapsa (I wrote) is an epistolary aorist, as the Cambridge Bible notes: John refers to the section about antichrists, using the past tense from the readers’ future perspective. Calvin observes that John concedes them a judgment by which they could distinguish truth from falsehood, not abstract knowledge but practical discernment guided by the Spirit. Barnes adds that the very fact they understand religion is the ground of John’s hope that his appeal will be effective. Gill echoes this: John writes not to ignorant persons but to knowing ones, to remind and establish them against deceivers. The final clause, no lie is of the truth, is, in Barnes’ words, a vital maxim: no error, however plausible, can have its origin in truth. Clarke connects it directly to the false teachers: their doctrine is a lie, and no lie can be consistent with Christianity. The consensus is clear: John writes to strengthen believers who already possess the truth, equipping them to reject lies precisely because they know the truth.
How settled is the interpretation?
Interpretive difficulty: Medium
Main views:
- Three-‘because’ reading (hoti = 'because' in all three): Supported by the Cambridge Bible and the RV: 'I have not written because you know not… but because you know it, and because no lie is of the truth.' This maintains parallel causal clauses.
- Mixed reading (AV: 'because…but because…and that'): The older English versions (KJV, Douay) treat the third hoti as a noun clause ('and that no lie is of the truth'), making the truth's nature the content of what they know.
- Epistolary aorist vs. simple past: The verb egrapsa may be an epistolary aorist (referring to this section, as Cambridge holds) or a simple past (referring to the entire letter, as some older commentators assume).
What is clear: John writes to affirm and remind believers who already possess the truth, and he asserts that nothing false can come from that truth, making them capable of rejecting lies.
What Scholars Agree and Debate
| Topic | Agreed | Debated |
|---|---|---|
| Meaning of 'I have written' (ἔγραψα) | It refers to the preceding section about antichrists, not the whole letter. Commentators accept the aorist tense as an epistolary aorist. | Some (like Cambridge) emphasize the epistolary aorist, while others (like Gill) treat it as a simple past referring to the entire epistle. The difference is minor and does not affect the main point. |
| Translation of the three occurrences of 'that' (ὅτι) | The first two (in v.21a) are most naturally read as 'because.' The third could be 'that' or 'because.' | Three options exist (Cambridge): (1) 'because…but because…and that' (AV); (2) 'because' in all three (RV); (3) 'that' in all three (almost certainly wrong, per Cambridge). The second reading is widely preferred because it keeps the logical flow consistent. |
| What 'no lie is of the truth' means practically | False doctrine cannot originate from or be consistent with the truth of the gospel. | Some see it as a general epistemological principle (Barnes), others as a specific reference to the antichristian lies of false teachers (Calvin, Clarke). The difference is one of scope, not contradiction. |
| The role of the reader's prior knowledge | John assumes his readers already know the truth through the Spirit's anointing. | Does this knowledge include every spiritual truth (Matthew Henry leans toward comprehensive knowledge via the Spirit) or only the essential apostolic tradition? Most commentators (Barnes, Calvin) take it as sufficient for discerning false teaching, not omniscience. |
Historical & Cultural Context
First John was written to a community of believers, likely in Asia Minor, with Ephesus as a traditional setting, facing the trauma of division. Verse 19 states that “they went out from us,” meaning false teachers had separated from the church. These teachers denied that Jesus is the Christ (v.22), a claim that threatened the core of Christian identity. John calls them antichrists and situates their appearance as a sign of the final hour (v.18).
In this crisis, the readers are not novices. Verse 20 says they “have an anointing from the Holy One” and “know all things.” This anointing is the Holy Spirit, the Spirit of truth, who indwells believers and teaches them (v.27). John’s purpose in v.21 is to clarify why he writes so urgently: not because his readers are ignorant, but because they already know the truth and can therefore detect what contradicts it.
The cultural context includes Jewish traditions of wisdom, where the wise person, not the fool, is the one who can receive instruction (Proverbs 1:5; 9:8-9). Greco-Roman rhetoric also valued “reminding” as a mark of respect toward knowledgeable audiences. John’s approach mirrors Paul’s in Romans 15:14-15 and Peter’s in 2 Peter 1:12: he writes to remind, not to introduce. The threat of deception was heightened by the seductive plausibility of the false teaching. John’s pastoral strategy is to ground his readers in what they already possess, the truth of the gospel and the Spirit’s guidance, so they can recognize any lie as alien to that truth.
Textual Notes
The supplied sources note no significant textual variants for 1 John 2:21. The Greek text is stable across the major manuscript traditions. The only variation among the supplied English translations is the rendering of the conjunction hoti, which is a matter of interpretation rather than textual difference.
Reception History
Early church writers such as Irenaeus and Tertullian appealed to this verse in their polemics against Gnostic teachers who claimed secret knowledge. John's assertion that the readers already know the truth, and that no lie can be part of it, undercut the Gnostic claim to a superior, hidden revelation. During the Reformation, the verse was used to affirm the clarity of Scripture and the Spirit's role in teaching believers directly, without the necessity of a magisterial interpreter. Reformed exegetes like Calvin and the Geneva Bible notes emphasized the practical discernment the Spirit gives. In the Wesleyan tradition, Adam Clarke connected the verse to the experiential knowledge of holiness. In modern evangelicalism, 1 John 2:21 is often cited in discussions about spiritual discernment, the sufficiency of biblical truth, and the confidence believers can have in the face of false teaching. Its pastoral tone, affirming what the reader already knows, has made it a favorite for those combating doctrinal division.
Preaching This Verse
Three-point outline
- The wrong assumption. John corrects any impression that he writes because his readers are ignorant. He is not scolding beginners; he is affirming seasoned believers.
- The real reason. He writes precisely because they know the truth. Knowledge isn’t the problem, it’s the foundation for discernment and stability against error.
- The sharp edge of truth. No lie comes from the truth. This is not just a logical truism but a pastoral filter: any teaching that contradicts what you have already received is disqualified at the start.
Five-point outline
- John’s readers have been shaken by the departure of false teachers (v.19).
- They possess the Spirit’s anointing and already know the truth (v.20).
- John’s letter is not a sign of their ignorance but a confirmation of their knowledge (v.21a).
- Because they know the truth, they can apply the rule: no lie originates from the truth (v.21b).
- This rule equips them to identify the liar, whoever denies Jesus is the Christ (v.22).
Illustration hooks
- The master chef. A cooking instructor doesn’t tell a skilled chef how to boil water. Instead, she says, “You know how to balance flavours, now trust that instinct and spot the bad recipe.” John treats his readers as competent to judge.
- Bank teller training. Tellers learn to spot counterfeit money not by studying every fake, but by handling the real currency so thoroughly that anything false feels wrong. John anchors his readers in the real thing.
- Parent with a teenager. A father sends a reminder text before a big test: “You know this material. You’ve studied. I’m texting to remind you of what you already know.” The tone is confidence, not correction.
Questions your congregation is asking
- “How can I be sure I’m not being deceived by a convincing teacher or pastor?”
- “If I already know the truth, why do I need to keep hearing sermons and reading the Bible?”
- “Does John mean that Christians possess all knowledge, or only the essential truths of the faith?”
Leading a Discussion
John writes to a community shaken by division. Some members have left the church, and their false teaching threatens those who remain. At this vulnerable moment, John does not treat his readers as raw beginners. He reminds them that they already know the truth and are equipped by the Spirit to recognize a lie when they see one. Your small group can explore what it means to be confident in what you know and how that confidence protects you from deception.
Discussion questions
- Read 1 John 2:18-21. What situation prompted John to write these words? (Notice v.19: “They went out from us.”)
- Verse 20 says the readers have “an anointing from the Holy One.” Based on v.27, what does this anointing enable them to do?
- Why does John say he wrote to them? Why is it important that he does not say he wrote because they are ignorant?
- The verse ends with the statement “no lie is of the truth.” Put this in your own words. Why is this statement more than an obvious fact in the context of false teachers?
- In what areas of life do you find it hardest to trust that you really know the truth? What helps you grow in confidence?
- Verse 22 identifies a specific lie, denying Jesus is the Christ. How does knowing the core truth about Jesus help you evaluate teachings you hear today?
- How can this passage encourage a church that has experienced a painful split or the departure of members who now teach something different?
Word Study
The key original-language words in this verse. Select any word for its full lexicon entry — meaning, every occurrence in Scripture, and related words.
Cross-References
Source: Treasury of Scripture Knowledge (TSK, public domain)
| Proverbs 1:5 | that the wise man may hear, and increase in learning; that the man of understanding may attain to sound counsel; |
| Proverbs 9:8 | Don’t reprove a scoffer, lest he hate you. Reprove a wise person, and he will love you. |
| Proverbs 9:9 | Instruct a wise person, and he will be still wiser. Teach a righteous person, and he will increase in learning. |
| Romans 15:14 | I myself am also persuaded about you, my brothers, that you yourselves are full of goodness, filled with all knowledge, able also to admonish others. |
| Romans 15:15 | But I write the more boldly to you in part as reminding you, because of the grace that was given to me by God, |
| II Peter 1:12 | Therefore I will not be negligent to remind you of these things, though you know them and are established in the present truth. |
| Jude 1:5 | Now I desire to remind you, though you already know this, that the Lord, having saved a people out of the land of Egypt, afterward destroyed those who didn’t believe. |
Interlinear and lexical data from STEPBible (CC BY 4.0). Cross-reference data from OpenBible.info (CC BY 4.0). Commentaries are public domain.
For personal reflection
Read the devotional page — prayer, application, and "for families"
What the Commentators Say
10 public-domain commentaries, condensed into plain language.
Adam Clarke's Commentary Methodist/Wesleyan 1826
Clarke notes that John writes not because his readers are ignorant, but because they already know the truth. Their knowledge equips them to recognize false teaching as a direct contradiction of what they have received. A lie, Clarke argues, cannot be consistent with Christianity.
Barnes' Notes on the Bible Protestant 1832
Barnes stresses that John writes to believers not because they lack knowledge, but because they already know the truth. He elevates this into a vital principle: no matter how plausible error appears or how good its temporary results, it can never be founded on truth. The only question that matters is what truth actually is.
Calvin's Commentaries Reformed 1564
Calvin stresses that John is not teaching a general philosophical rule about how falsehood differs from truth. Instead, he describes a practical gift: believers are so fortified by the Spirit that they can readily recognize any deception Satan might devise, not just obvious falsehoods.
Cambridge Bible for Schools and Colleges Anglican 1880
The commentary distinguishes three possible readings of the Greek conjunction in this verse. It argues the best interpretation takes all three instances as "because": John writes not because his readers are ignorant of the truth, but because they already know it, and because every lie is utterly alien to that truth.
Geneva Bible Notes Reformed 1599
The Geneva note draws attention to the writer's reassurance: the letter is not a correction of ignorance but a reminder to those who already know the truth. Its distinctive point is the principle that a lie cannot come from what is true, reinforcing the sharp boundary between truth and falsehood.
Gill's Exposition of the Bible Baptist 1748
Gill explains that John wrote not because his readers were ignorant, but precisely because they already knew the truth in its fullness. The purpose was to remind and strengthen them against deceivers, since lies are the direct opposite of truth and can never come from it.
Jamieson-Fausset-Brown Commentary Protestant 1871
JFB stresses that knowing the truth naturally enables believers to spot a lie, just as a straight line reveals what is crooked. Their knowledge makes deception unmistakable, because no lie has any share in the truth.
Matthew Henry's Commentary Reformed/Presbyterian 1710
Matthew Henry highlights that true Christians receive a heavenly anointing from the Holy One, the Spirit of grace, that sets them apart as anointed ones sharing in Christ's offices as prophets, priests, and kings. This unction gives them spiritual knowledge and stability to stand firm against seducers.
Vincent's Word Studies Evangelical 1887
Vincent notes that the Greek phrase can be rendered either "I have not written" or "I wrote not," pointing to a difference in how English captures the past tense. He directs the reader to his note on verse 13 for further explanation.
Wesley's Explanatory Notes Methodist/Wesleyan 1754
I have written - Namely, 1 Jo 2:13 . To you because ye know the truth - That is, to confirm you in the knowledge ye have already. Ye know that no lie is of the truth - That all the doctrines of these antichrists are irreconcilable to it.