Many a Protestant has glossed over 1 John 5:16-18 where it states not to pray for people with a certain sin, that it may be forgiven.
From these verses, Catholics try to claim there is a Biblical basis for differentiating between sins (something the Eastern and Oriental Orthodox do not do.) Catholic.com states, “These verses cannot be any plainer that there is such a thing as ‘deadly sin’ and ‘sin which is not deadly.’ That is precisely what the Church means by mortal (sin unto death) and venial (sin not unto death) sin.”
However, there are two extremely obvious problems with the Catholic contention which make it honestly surprising that Catholics would even go to these verses to prove their “unbiblical” and “untraditional” view of sin.
The first reason is a short one: “There is a sin leading to death; I do not say that he should make request for this” (1 John 5:16). Yet, Catholics believe that mortal sins can be forgiven through honest confession and penitence. “The priest will begin the Confession with the prayer of the Sign of the Cross,” says a Catholic website. Yet, the Bible specifically says that one should not request for forgiveness for such a sin!
A lot of Catholic theologians should lose their jobs for that shoddy sort of exegesis!
The second reason is also simple, but merits more explanation: “There is a sin…” John has in mind a specific sin and this is how early church fathers, like Augustine, understood the verse. If what Catholicism teaches now was always the historical teaching of the church, how was Augustine unaware of their present exegesis being the singular explanation of the Church?
Augustine writes that, “Concerning which sin (since it is not expressed) many and different notions may be entertained” (A Treatise on Rebuke and Grace, Chapter 35). This shows that the present Catholic explanation of the verse was not the only one, even if similar ideas are communicated in Cassian’s Conferences 11 Chapter 9 and Ambrose’s On Repentance, Book 1, Chapter 12. Nonetheless, Augustine continues:
I, however, say, that sin is to forsake even unto death the faith which worketh by love. This sin they no longer serve who are not in the first condition, as Adam, free; but are freed by the grace of God through the second Adam, and by that deliverance have that free will which enables them to serve God, not that by which they may be made captive by the devil. From being made free from sin they have become the servants of righteousness, in which they will stand till the end, by the gift to them of perseverance from Him who foreknew them, and predestinated them, and called them according to His purpose, and justified them, and glorified them, since He has even already formed those things that are to come which He promised concerning them.
The former underlined shows Augustine’s explanation. Rejecting faith is the singular sin one cannot ask forgiveness for. This is a Biblically consistent explanation, as we are saved by faith alone and apart from faith cannot be saved from our sin. Furthermore, it fits the passage which identifies a singular sin as the one not to make request for. I underline the latter simply because it gives us encouragement that those of us who have faith in Christ will be given the gift of perseverance to the end.
Augustine elsewhere uses the same exegesis of 1 John 5:16. In his homilies on the letter he says of the verse, “On the other hand, the apostle Paul does not pray for Alexander, and the reason I suppose, is, that this man was a brother, and had sinned ‘unto death,’ i.e. by opposing the brotherhood in a spirit of hatred.” As we can see, the sin onto death is not having faith that works through love.
So, does 1 John 5:16-18 talk about mortal and venial sins? The answer would be no. Is this only a position that an out-there, guy alone in the woods with the Bible, can come up with? No again. Not only the wording of the verse encourages against such an explanation, Augustine appears to be aware of Ambrose’s view and purposely rejects it for a much more sensible one. The only sin onto death is rejecting Jesus Christ, because He is the only way to the Father. Case closed.