There is a death beyond which you cannot imagine. There is a thing which can kill you forever and from which there is no relief.

That thing is mortal sin.

Mortal sin is that sin in which you cut yourself off from God completely, from which there is no eternal life if you die with it on your soul. You condemn yourself to Hell for all eternity.

1 John 5:16-17;

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.

The Catechism of the Catholic Church discusses mortal sin at length in the following paragraphs:

1855
Mortal sin destroys charity in the heart of man by a grave violation of God’s law; it turns man away from God, who is his ultimate end and his beatitude, by preferring an inferior good to him.

Venial sin allows charity to subsist, even though it offends and wounds it.

1856
Mortal sin, by attacking the vital principle within us—that is, charity—necessitates a new initiative of God’s mercy and a conversion of heart which is normally accomplished within the setting of the sacrament of reconciliation:

When the will sets itself upon something that is of its nature incompatible with the charity that orients man toward his ultimate end, then the sin is mortal by its very object . . . whether it contradicts the love of God, such as blasphemy or perjury, or the love of neighbor, such as homicide or adultery. . . . But when the sinner’s will is set upon something that of its nature involves a disorder, but is not opposed to the love of God and neighbor, such as thoughtless chatter or immoderate laughter and the like, such sins are venial.

1857
For a sin to be mortal, three conditions must together be met: “Mortal sin is sin whose object is grave matter and which is also committed with full knowledge and deliberate consent.”

1858
Grave matter is specified by the Ten Commandments, corresponding to the answer of Jesus to the rich young man: “Do not kill, Do not commit adultery, Do not steal, Do not bear false witness, Do not defraud, Honor your father and your mother.” The gravity of sins is more or less great: murder is graver than theft. One must also take into account who is wronged: violence against parents is in itself graver than violence against a stranger.

1859
Mortal sin requires full knowledge and complete consent. It presupposes knowledge of the sinful character of the act, of its opposition to God’s law. It also implies a consent sufficiently deliberate to be a personal choice. Feigned ignorance and hardness of heart do not diminish, but rather increase, the voluntary character of a sin.

1860
Unintentional ignorance can diminish or even remove the imputability of a grave offense. But no one is deemed to be ignorant of the principles of the moral law, which are written in the conscience of every man. The promptings of feelings and passions can also diminish the voluntary and free character of the offense, as can external pressures or pathological disorders. Sin committed through malice, by deliberate choice of evil, is the gravest.

1861
Mortal sin is a radical possibility of human freedom, as is love itself. It results in the loss of charity and the privation of sanctifying grace, that is, of the state of grace. If it is not redeemed by repentance and God’s forgiveness, it causes exclusion from Christ’s kingdom and the eternal death of hell, for our freedom has the power to make choices for ever, with no turning back. However, although we can judge that an act is in itself a grave offense, we must entrust judgment of persons to the justice and mercy of God.

I write about this as there is the real possibility of mortal sins having been committed in our alcoholic past. Granted that there is a serious mitigating factor in that our will was compromised by our addiction, but still our moral reasoning may be in need of correction after sobering up. A strong examination of our alcoholic past in our moral inventory is likely to turn up some unsavory behaviors. Exposing them to another in 12 Step work isn’t enough. It does help clear the past and set us on a straighter moral path, but the stain of sin remains from these past actions.

These need to be taken care of in our return to the Sacrament of Confession. The chance need not be risked that our alcoholism or any other addiction can be used as an excuse to avoid Confession.

Supposition that we’ve suffered enough from them is not good enough, we need the sacramental graces from Confession and the absolution cleansing our soul to save us from damnation.

Our eternal life depends upon it.

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