What is the sin that is unto death?                                                             by Jack Kettler


“If any man sees his brother sin a sin which is not unto death, he shall ask, and he shall give him life for them that sin not unto death. There is a sin unto death: I do not say that he shall pray for it.” (1 John 5:16)


1.      What is a sin unto death?

2.      Can this sin be identified by one who is committing it or observing it?

3.      Can a Christian commit this sin?


The passage from 1 John has been one of the more difficult texts to interpret.


Some distinctions:


First, the Apostle addresses a sin that is not unto death and can be committed by a brother, 5:16a.


Second, 1 John 5:16a involves prayer. 1 John 5:16b seemingly does not include prayer.


The following observation may help to answer the second question:


1 John 5:16a is regarding a brother. However, 1 John 5:16b seemingly does not have a brother in view.


Many expositors and commentators have noted these distinctions.


One possible interpretation: 


Is 1 John 5:16 the same as blaspheming against the Spirit seen in Matthew 12:31?


In Matthew 12:31, blasphemy against the Spirit is mentioned. Is this blasphemy a sin unto death? Is blasphemy against the Holy Spirit accusing Jesus Christ of being demon-possessed instead of filled with the Spirit? Blasphemy of this nature seems probable. The standard interpretation is that the unpardonable sin today is remaining in the state of unbelief.


If this is correct, then 1 John 5:16, b could not be talking about blasphemy against the Holy Spirit since the restriction about not praying for this sin would be inconsistent with other Scriptures about praying for the lost.


One possible interpretation of 1 John 5:16 is what happened to Ananias and Sapphira in Acts 5:1–10. However, after consulting the Cambridge Bible for Schools and Colleges, as will be seen, it seems to rule this out under point number two.


Cambridge Bible for Schools and Colleges:


“There is a sin unto death Or, there is sin unto death; we have no τις or μία in the Greek, a fact which is against the supposition that any act of sin is intended. In that case would not S. John have named it, that the faithful might avoid it, and also know when it had been committed? The following explanations of ‘sin unto death’ may be safely rejected. 1. Sin punished by the law with death. 2. Sin punished by Divine visitation with death or sickness. 3. Sin punished by the Church with excommunication. As a help to a right explanation we may get rid of the idea which some commentators assume, that ‘sin unto death’ is a sin which can be recognised by those among whom the one who commits it lives. S. John’s very guarded language points the other way. He implies that some sins may be known to be ‘not unto death’: he neither says nor implies that all ‘sin unto death’ can be known as such. As a further help we may remember that no sin, if repented of, can be too great for God’s mercy. Hence S. John does not speak even of this sin as ‘fatal’ or ‘mortal’, but as ‘unto death’ (πρὸς θάνατον). Death is its natural, but not its absolutely inevitable consequence. It is possible to close the heart against the influences of God’s Spirit so obstinately and persistently that repentance becomes a moral impossibility. Just as the body may starve itself to such an extent as to make the digestion, or even the reception, of food impossible; so, the soul may go on refusing offers of grace until the very power to receive grace perishes. Such a condition is necessarily sin, and ‘sin unto death’. No passing over out of death into life (1 John 3:14) is any longer (without a miracle of grace) possible. ‘Sin unto death’, therefore, is not any act of sin, however heinous, but a state or habit of sin wilfully chosen and persisted in: it is constant and consummate opposition to God. In the phraseology of this Epistle we might say that it is the deliberate preference of darkness to light, of falsehood to truth, of sin to righteousness, of the world to the Father, of spiritual death to eternal life.” (1) (Underlining and bolding emphasis mine)


The Cambridge commentators rightly note that if John could identify the sin, he would be able to warn believers of this sin. However, since John does not identify the sin unto death, the following possibilities are ruled out, “1. Sin punished by the law with death. 2. Sin punished by Divine visitation with death or sickness. 3. Sin punished by the Church with excommunication.”


Calvin on 1 John 5:16:


“But among the faithful, this ought to be an indubitable truth, that whatever is contrary to God's law is sin, and in its nature mortal; for where there is a transgression of the law, there is sin and death.


What, then, is the meaning of the Apostle? He denies that sins are mortal, which, though worthy of death, are yet not thus punished by God. He therefore does not estimate sins in themselves, but forms a judgment of them according to the paternal kindness of God, which pardons the guilt, where yet the fault is. In short, God does not give over to death those whom he has restored to life, though it depends not on them that they are not alienated from life.


There is a sin unto death I have already said that the sin to which there is no hope of pardon left, is thus called. But it may be asked, what this is; for it must be very atrocious, when God thus so severely punishes it. It may be gathered from the context, that it is not, as they say, a partial fall, or a transgression of a single commandment, but apostasy, by which men wholly alienate themselves from God. For the Apostle afterwards adds, that the children of God do not sin, that is, that they do not forsake God, and wholly surrender themselves to Satan, to be his slaves. Such a defection, it is no wonder that it is mortal; for God never thus deprives his own people of the grace of the Spirit; but they ever retain some spark of true religion. They must then be reprobate and given up to destruction, who thus fall away so as to have no fear of God.


Were any one to ask, whether the door of salvation is closed against their repentance; the answer is obvious, that as they are given up to a reprobate mind, and are destitute of the Holy Spirit, they cannot do anything else, than with obstinate minds, become worse and worse, and add sins to sins.


But it may be asked again, by what evidences can we know that a man's fall is fatal; for except the knowledge of this was certain, in vain would the Apostle have made this exception, that they were not to pray for a sin of this kind. It is then right to determine sometimes, whether the fallen is without hope, or whether there is still a place for a remedy. This, indeed, is what I allow, and what is evident beyond dispute from this passage; but as this very seldom happens, and as God sets before us the infinite riches of his grace, and bids us to be merciful according to his own example, we ought not rashly to conclude that any one has brought on himself the judgment of eternal death; on the contrary, love should dispose us to hope well. But if the impiety of some appear to us not otherwise than hopeless, as though the Lord pointed it out by the finger, we ought not to contend with the just judgment of God, or seek to be more merciful than he is.” (2)


As Calvin notes, “They must then be reprobate and given up to destruction, who thus fall away so as to have no fear of God.” In this respect, Calvin equates the “sin unto death” with the sin of final apostasy.


From Spurgeon's Expositions of the Bible on the 1 John passage:


“1 John 5:16-18. If any man sees his brother sin a sin which is not unto death, he shall ask, and he shall give him life for them that sin not unto death. There is a sin unto death: I do not say that he shall pray for it. All unrighteousness is sin: and there is a sin not unto death. We know that whatsoever is born of God sinneth not; but he that is begotten of God keepeth himself, and that wicked one toucheth him not.


He who has committed the sin which is unto death have no desire for forgiveness, he will never repent, he will never seek faith in Christ but he will continue hardened and unbelieving; he will henceforth never be the subject of holy influences, for he has crossed over into that dark region of despair where hope and mercy never come. Perhaps some of you think that you have committed that unpardonable sin, and are at this moment grieving over it. If so, it is clear that you cannot have committed that sin, or else you could not grieve over it. If you have any fear concerning it, you have not committed that sin which is unto death, for even fear is a sign of life. Whoever repents of sin and trusts in Jesus Christ is freely and fully forgiven, therefore it is clear that he has not committed a sin which will not be forgiven. There is much in this passage to make us prayerful and watchful, but there is nothing here to make a single troubled heart feel anything like despair. He that is born again, born from above, can never commit this unpardonable sin. He is kept from it; “that wicked one” cannot even touch him, for he is preserved by sovereign grace against this dreadful damage to his soul. You need not be curious to enquire what this unpardonable sin is. I will give you an old illustration of mine concerning it. You may sometimes have seen a notice put up on certain estates in the country, “Man-traps and spring guns set here,” but, if so, did you ever go round to the front door of the mansion, and say, “If you please will you tell me where the man-traps are, and whereabouts the spring guns are set?” If you had asked that question, the answer would have been, “It is the very purpose of this warning not to tell you where they are, for you have no business to trespass there at all.” So, “all unrighteousness is sin,” and you are warned to keep clear of it.” There is a sin unto death,” but you are not told what that sin is on purpose that you may, by the grace of God, keep clear of sin altogether.” (3)


As noted by Spurgeon, this “sin unto death” cannot be committed by a true Christian.  


In closing:


In this final contribution, a look at the grammar and possibilities of a different translation of the text is explored to find a solution to understanding what John had in mind.




V. Conclusion p. 608


Arguments from grammatical usage and from the flow of John’s argument

in 1 John point towards an alternative interpretation of 1 John 5:16–17:

(a) because the main verb levgw, “I speak,” comes between the prepositional

phrase “not concerning that” and the ªna-clause, NT usage heavily favors

taking the prepositional phrase with “I speak”; (b) John’s normal usage of

o§ti and ªna-clauses favors taking the ªna-clause here as a purpose clause,

“in order that he might supplicate”; and (c) the immediate context of 1 John

5:13–17 and the principle of maximal redundancy favor this reading.


The resulting translation is: “If anyone should see his brother practicing

a sin that does not lead to eternal death, he shall supplicate God and he shall

give him eternal life for those who are sinning not unto eternal death. There

is sin that leads to eternal death. I am not speaking concerning that sin that

leads to eternal death in order that he might supplicate God for the brother

whom he sees sinning. 40 For while all unrighteousness is sin, there is sin that

does not lead to eternal death.”


John’s purpose is to assure Christians of the efficacy of their prayers for

fellow members of the Christian community who fall into sin: our intercessory

prayers will certainly restore them to fellowship with God (tantamount

to having eternal/resurrection life in John’s writings, since God is the only

source of life), with one exception. While John acknowledges that there is

this exception, a category of sin that leads to eternal death, he does not wish

to focus on it because his purpose is to call believers to intercessory prayer.

Intercession thus appears to be one of the ways in which Christians are

to bear one another’s burdens (cf. Gal 6:1–2). Ultimately, each individual


40 John’s interchange of ejrwtaÅn with a√te∂n in John 16:23 and 26 shows that no difference in

meaning should be posited between these two verbs. John 16:26 also points the way to the words

that I supplied above: one supplicates God for people. John 17:9 shows how the one to whom one

supplicates can be omitted after the referent is established in context. Cf. notes 18 and 35. The

attempt to distinguish ejrwtaÅn from a√te∂n as indicating a more intimate relationship between the

one praying and the one addressed (see e.g. Westcott, The Epistles of John 192; G. Stahlin, “a√tevw,

ktl.” TDNT 1.193; and H. Greeven, “eußcomai, ktl.” TDNT 2.806) seems ill-founded


John’s confidence in 1 John 5:16–17 p. 609


must bear his or her own burden (individual responsibility; Gal 6:5). Each

must confess sin, repent, and believe the gospel for himself or herself (cf.

1 John 1:5–2:2). 41 Yet Christians who acknowledge John’s authority would

do well to heed his call to intercession. We can be confident that it is God’s

will that we intercede for a brother or sister who falls into sin and that our

intercessions will avail. If our intercessions do not ultimately avail, we will

know after the fact that this person has committed sin that leads to eternal

death (1 John 5:16b) and that he or she was never really part of the true

Christian community (1 John 2:19).


Ultimately, only God knows every heart, and we should leave all matters

in his hands. At the same time, we should not allow uncertainty over

whether a member of the visible Christian community has sinned or strayed

in a way that casts doubt on the genuineness of his or her faith keep us

from making fervent and persevering intercession for that person. Just as

we should humbly seek to instruct and correct, we should intercede with God

on behalf of straying brethren, “if perhaps God might grant them repentance leading to the knowledge of the truth” (2 Tim 2:25). 42


41 One should not vainly hope that one’s conversion or restoration from straying would come

through others’ intercession apart from humbling oneself in personal confession of sin, repentance,

and renewed faith.

42 1 John 5:16–17 represents just one aspect of how the Christian community should deal with

straying members of the community. Other equally important aspects are brought out by pas-                         

sages like Matt 18:15–22; Luke 17:3–4; 1 Cor 5:1–6:11; 2 Cor 2:6–11; Gal 6:1–2; 2 Thess 3:14–15;

1 Tim 1:20; and James 5:15, 19–20. A balanced application of biblical teaching would neither

neglect intercession nor privilege it to the expense of the other aspects. Furthermore, anyone who

is in sin or contemplating sin should not reason perversely that since intercession, repentance,

and forgiveness are readily available, one might as well sin with impunity and seek restoration

later. For a helpful treatment of perseverance and assurance, see Thomas R. Schreiner and Ardel

B. Caneday, The Race Set Before Us: A Biblical Theology of Perseverance & Assurance (Downers

Grove/Leicester: InterVarsity, 2001) (4)


To answer the starting questions:


What is a sin unto death?

This question cannot be answered with certainty. From the commentary evidence surveyed above, the sin unto death would be final apostasy.


Can this sin be identified by one who is committing it or observing it?

Like the first question, this question likewise cannot be answered with certainty.


Can a Christian commit this sin?

If the sin unto death is final apostasy, then no, a Christian cannot commit it.


Concluding comment:


In light of the fourth entry by Randal K. J. Tan, the highlighted text seems to clarify the mystery of the “sin unto death.” Therefore, it was not John’s purpose at all to identify this sin; the text is an encouragement for intercessory prayers to fellow believers.



For more research:


Pastor theologian Sam Storms has a comprehensive analysis of 1 John 5:16 that can be found at, https://www.monergism.com/can-christian-commit-sin-unto-death




“Study to shew thyself approved unto God, a workman that needeth not to be ashamed, rightly dividing the word of truth.” (2 Timothy 2:15)




1.      The Epistles of John, The Cambridge Bible for Schools, Alfred Plummer, (Cambridge University Press, 1898), e-Sword version.

2.      John Calvin, Calvin's Commentaries, 1 John, Volume XXII, (Grand Rapids, Michigan, Baker Book House Reprinted 1979), pp. 268-269.

3.      Spurgeon, Charles Haddon, “Commentary on 1 John 5,” “Spurgeon's Verse Expositions of the Bible” Online resource.

4.      Journal of Evangelical Theology Society, (JETS) 45/4 (December 2002) 599–609



Mr. Kettler has previously published articles in the Chalcedon Report and Contra Mundum. He and his wife Marea attend the Westminster, CO, RPCNA Church. Mr. Kettler is the author of books defending the Reformed Faith. Books can be ordered online at www. JackKettler .com