What is the difference between "Mortal Sin" in the Catholic Church and "Serious Sin" in the Orthodox Church

We got an email that said:

Eastern Orthodox do not generally accept Roman terms such as "mortal sin."  But, as to Eastern Catholic's, they appear bound by Roman theology in this area.  Catholic Canon Law, specifically, canon 711 of the Code of Canons of the Eastern Churches (http://www.intratext.com/IXT/ENG1199/_PJR.htm) requires a person to abstain from communion if he is conscious of "serious sin."  Is this different than the Roman concept of "mortal sin"?  If not, isn't this an instance of forcing Western rules on the East?

Mark Bonocore responds:

First of all, I must dispute the contention that Eastern Orthodox Christians do not accept the concept of "mortal sin" or that mortal sin is merely a "Roman concept."   It is a Scriptural concept. For example, the Apostle John in 1 John 5:16-17 says ...

"If anyone sees his brother sinning, if the sin is not deadly, he should pray to God and He will give him life.  This is only for those whose sin is not deadly.  There is such a thing as deadly sin, about which I do not say that you should pray.  All wrongdoing is sin, but there is sin that is not deadly." 

This is what the Roman term "mortal sin" refers to --from the Latin term for death or deadly: "mortus."    And while Eastern Orthodox (and Eastern Catholics) may not use the term "mortal sin," they most certainly (if they are orthodox) subscribe to the concept, as found right here in 1 John 5 and throughout Apostolic Tradition. No Apostolic Church has ever permitted someone to receive the Sacraments (especially the Eucharist) if they committed a sin that directly denied their Baptismal vows ---that is, a sin that effectively separates the sinner from the Church. This is what we Romans call "mortal sin."   The Eastern Catholic Code of Canon Law does not use the term "mortal sin" because the term is a Latin one, and thus alien to Eastern tradition. This is why the term "serious sin" is used instead. But, it essentially refers to the same thing as mortal sin, yes. 

Now, if an Eastern Orthodox prelate is (incorrectly) saying that the Eastern Orthodox Church does not subscribe to a concept of sin which requires the sinner to be excluded from the Sacraments (until they repent, of course), then the question to ask him is, if the Eastern Orthodox Church subscribes to 1 John 5:16-17 or not.  

We are not imposing Roman theology on Eastern Catholics. If anything, some Eastern Orthodox have neglected Apostolic practice (as they have in many areas) in this regard, and the Eastern Catholic code of canon law merely upholds the Apostolic discipline. Committing serious (i.e., mortal or deadly) sin separates a Christian from the communion of the Church, and the Christian is required to seek reconciliation with the Church before he can partake of the Eucharist, which is our Sacrament of unity and the manifestation of the Church as one Body in Christ.    Someone who receives the Eucharist while in a state of unrepentant "deadly sin" is lying to Christ and to the rest of the Church, and committing sacrilege against the Body and against the Holy Spirit. They are claiming to be in union with the Body of Christ when they are not.   This is why, in regard to the sin of fornication (to cite just one example of "deadly sin"), St. Paul says ...

"Do you not know that your bodies are members of Christ?   Shall I then take the members of Christ and make them members with a prostitute?  Of course not!   Or do you not know that anyone who joins himself to a prostitute becomes one body with her?  'For 'the two,' it says, 'will be one flesh.'   But, whomever is joined to the Lord becomes one spirit with Him.  ...Therefore, glorify God in your body."  

St. Paul's meaning here has to do with the Church as the Body of Christ --a mysterious extension of His own Incarnation. What he's saying is the sin separates us from the Body of Christ; for (in this example), we cannot be both one-Flesh with Christ and one-flesh with a prostitute. If we have sex with a prostitute, we have separated ourselves from the Body of Christ, since Christ cannot be one-Flesh with anyone in sin. And, if we have separated ourselves from the Body, then we have cut ourselves off from the source of eternal life --i.e., we have committed a "deadly sin."   So, those who have committed this "deadly sin" (or any other kind of deadly sin) MUST be reconciled with Christ in His Body, the Church. Otherwise, they may not call themselves true Christians or participate in the Sacramental life of the Church. Or, to put it in pure Eastern language:  How can someone partake of the Mystery of the Eucharist when they have separated themselves (by their sin) from the Mystery of the Body of Christ (i.e., the Church)???   All is part of the very same Mystery (Mysterion). The Eastern Catholic code of canon law is merely upholding this truth. Our Eastern Christian replies:

However, I would take issue with some of the representations you make.  First of all, Its important to remember that "serious" sin does not exactly equate to the sins understood by Latin Catholics to be "mortal" sins or "grave" sins.  Its not an exact match.  Likewise, I would suggest that the Biblical passages you cite may not be interpreted the exact same way in the Eastern Churches.  I don't have the experise to write more on this in a definitive way, or I would.  But, texts exist, even in the Eastern Catholic Churches, that support my points. <<<

While we Romans would agree that there does exist a distinction between what we might call "serious sin" vs. sin that is truly "mortal," that in itself would be a Roman theological distinction.  :-)   The reference in the Eastern code of canon law is not trying to make such a "Roman" distinction. Rather, what it is trying to do is present the concept (of sins which prevent one from worthily receiving the Eucharist) in a non-Roman way. In other words, it is talking about what we Romans would call "mortal sin," but which the East does not approach in those terms. And that is fine. 

Secondly, in Roman semantics, "mortal sin" does not equal "grave sin" per se. Rather, "grave sin" would be equivalent to what we would call "serious sin."   ....and, in the Roman theological mentality, this would be a sin that would cause truly serious damage to the sinner, but which was performed under circumstances in which the sinner did not incur the full guilt that would apply to a truly mortal sin. For example ... returning to the prostitute example that I used in the last email (illicit sex always seems to be good for such illustrations ;-)), if a married man is tempted to cheat on his wife, but tries his very best to escape the temptation; but then if a situation is such that, despite his best efforts to be faithful, and against all possible human endurance, he succumbs to temptation, then we would say that this may qualify as a sin which is "serious" but not necessarily "mortal."  ...and this is because the man sincerely tried his best, but simply did not have his mental faculties when he succumbed to the sin. Thus, he manifested the full damage of fornication, but not the full guilt. But, again, this is a Roman distinction employing a Roman mentality. The Eastern code intends to refer to the Apostolic mystery that we Romans call "mortal sin" (sin that separates the sinner from the Church) using non-Roman terminology. 

Thirdly ... 1 John 5 only speaks of "deadly" and "not deadly" sins. There is no mention of "serious" sin in the context that St. John is addressing, which has to do with remaining within the Church. As you may know, in the original discipline of the Apostles (and the practice of the Church up until A.D. 217), if one committed what St. John calls "deadly sin" after Baptism, one was formally excommunicated from the Church, often until one's deathbed. Only then (and only once in one's lifetime) could a sinner receive the Sacrament of Confession. But, this original discipline was changed in A.D. 217 by Pope St. Callistus I who, for the first time in Christian history, permitted repeated sinners to remain in full communion with the Church, allowing them to receive Confession repeatedly as they struggle to overcome their sin. And this is why both Catholics and Eastern Orthodox can receive Confession repeatedly today, and why we are not formally excommunicated when we commit "deadly" (mortal) sins. We today of course take this for granted; but when Pope St. Callistus  --invoking his Petrine authority to "bind and loosen" --first relaxed the original discipline in A.D. 217, he was attached on both the extreme "right" by ultra-conservative St. Hippolytus and on the "left" by Tertullian, who was a Montanist heretic at the time; and both accused him of departing from Apostolic Tradition. For example, Tertullian writes, mocking Pope Callistus and calling him the "Pontifex Maximus," which was a pagan title at the time (the head of the Roman state religion) ....

“In opposition to this [modesty], could I not have acted the dissembler? I
hear that there has even been an edict sent forth, and a peremptory one too.
The ‘Pontifex Maximus,’ that is the ‘bishop of bishops,’ issues an edict: ‘I
remit, to such as have discharged [the requirements of] repentance, the sins
both of adultery and of fornication.’ O edict, on which cannot be inscribed,
‘Good deed!’ ...Far, far from Christ's betrothed be such a proclamation! (_On
Modesty_ 1.1, ANF IV:74).

...and ...

I now inquire into your opinions, to see whence you usurp the right for the
Church.  Do you presume, because the Lord said to Peter, 'On this rock I
will build my Church ...[Matt 16-19]'  that the power of binding and loosing has
thereby been handed over to you*, that is, to every church akin to that of Peter?
What kind of man are you, subverting and changing what was the manifest
intent of the Lord when He conferred this personally on Peter?  'On
you,' He says, 'I will build my Church; and I give to you the keys'...."
(Tertullian, On Modesty 21:9-10) 

So, what we can see here is that Pope Callistus' "edict" (relaxing the original discipline) was a universal decree, and he based it on his claimed succession from St. Peter, and Peter's Christ-given authority to "bind and loosen."   As far as we know, this is the first historical example that we have of a Pope claiming this specific Petrine authority. But, what cannot be disputed is that, with the exception of St. Hippolytus and the Montanists, the entire early Church accepted this transition, and thus both East and West practice repeated Confession today and do not formally excommunicate someone for committing "deadly sins."    Rather, despite the fact that these repeated sinners (which now consists of most Catholics and Eastern Orthodox living today) have violated their Baptismal vows, they are permitted to remain within the all-holy Church, NOT because they (like the saints) deserve to be, but out of INDULGENCE --that is, the indulgence (i.e., toleration) of Christ and the saints, who permit them to remain in the Body despite their shortcomings and lack of holiness --their infidelity being made up for by the fidelity of the saints who maintain communion with them (e.g. 1 Corinth 12:26). . And the entire Western theology of indulgences is built upon this principal (established in A.D. 217). Now it is true that the developed Western theology of "indulgences" is alien to the East. But, the 3rd Century principal upon which it is based is held in common by both East and West ...and this is the Apostolic understanding that "deadly sin" is a reality and that an unrepentant sinner may not partake of the Eucharist. HOW we put this principal into action (that is, what kind of practical discipline we use) may be different. But, the principal itself is Apostolic and not debatable. 

And, lastly, and intimately connected to this .... If you think that the East understands and interprets 1 John 5:16-17 differently than we do, then I would encourage you to ask your Eastern prelates about it and see if there is any possible way to "get around" the obvious interpretation that I provided. St. John clearly says that there are "deadly" and "not deadly" sins --that is, sins which lead to spiritual death and sins which do not lead to spiritual death. Those who are within the Church are immune from spiritual death. Rather, death is only upon us when we are separated from the Church. This is the Apostolic understanding. And, again, do you think that someone who is spiritually dead, and thus essentially outside the Church, should be free to receive Holy Communion with the Church?    This is the issue that you raise. But, the answer is pretty straight-forward.