Biblion Bible Commentary
Read the introduction to 1 John · About this commentary
A Sin Leading to Death
1 John 5:16-17
16 If anyone sees his brother sinning a sin not leading to death, he shall ask, and God will give him life for those who sin not leading to death. There is sin leading to death. I don’t say that he should make a request concerning this. · WEB
The passage that most resists certainty is left where the letter leaves it, and what the letter does say is that the reader's job is to pray.
The instruction is clear even where the category is not. Seeing a brother sin, the reader is to ask, and God will give him life. Prayer for another person is presented as ordinary and effective, which follows directly from the two verses before it 1 John 5:14–15.
Then the exception: there is sin leading to death. I do not say that he should make request concerning this.
The gap the letter leaves is a gap it chose. The sin is not identified, not described, and not illustrated. Several identifications are possible from elsewhere in Scripture and the letter supplies none, so any name proposed would be an addition to the text at exactly the point where the text declines to speak.
Three things can be said without adding anything. The letter does not forbid praying — it says only that it is not commanding it, which is a narrower statement than a prohibition. It gives the reader no method for identifying such a sin in another person, which means the passage cannot function as a licence to write anyone off. And its subject throughout is what to do, not how to classify: the instruction that occupies the passage is to pray, and the exception is a single clause inside it.
Verse 17 then widens the frame again, and it is a mercy that it does: all unrighteousness is sin, and there is sin not leading to death.
one view among several What this mark means