So what kind of Sins are Mortal?
In order for a sin to be mortal, it must meet three conditions:
This means that mortal sins cannot be done “accidentally.” A person who commits a mortal sin is one who knows that their sin is wrong, but still deliberately commits the sin anyway. This means that mortal sins are “premeditated” by the sinner and thus are truly a rejection of God’s law and love.
The first condition, that a mortal sin is of grave matter, means that certain premeditated offenses against God are more severe than others. We know that some sins are graver than others (e.g. it is a graver sin to murder someone than to lie to someone). St. John tells us, “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.” (1 John 5:16-17). Thus St. John distinguishes between mortal and venial sin. Jesus also warns us that “Anyone who does not remain in me will be thrown out like a branch and wither; people will gather them and throw them into a fire and they will be burned” (John 15:6).
What kinds of offenses against God constitute “grave matter”?
In the Bible, St. Paul gives us a list of grave sins. He states that anyone who commits these sins shall not enter the kingdom of God. “Now the works of the flesh are manifest, which are these; Adultery, fornication, uncleanness, lasciviousness, idolatry, witchcraft, hatred, variance, emulations, wrath, strife, seditions, heresies, envyings, murders, drunkenness, revellings, and such like: of the which I tell you before, as I have also told you in time past, that they which do such things shall not inherit the kingdom of God” (Galatians 5:19-20). Paul also tells the Corinthians, “know you no that the unjust shall not possess the kingdom of God? Do not err: neither fornicators, nor idolaters, nor adulterers, Nor the effeminate, nor liers with mankind, nor thieves, nor covetous, nor drunkards nor railers, nor extortioners shall possess the kingdom of God” (1 Corinthians 6:9-10). These sins constitute grave matter, and if they are committed willingly and with full consent, constitute mortal sin.
The Church also tells us that the sins of anger, blasphemy, envy, hatred, malice, murder, neglect of Sunday obligation, sins against faith (incredulity against God or heresy), sins against hope (obstinate despair in the hope for salvation and/or presumption that oneself can live without God or be saved by one’s own power) and sins against love (indifference towards charity, ingratitude, and/or hatred of God) also constitute grave matter. This list of grave sins, is based on Jesus Christ’s interpretation of the gravity of the Ten Commandments. Grave sins can be classed as sins against God, neighbor and self, and can further be divided into carnal and spiritual sins (CCC 1853).
Four other sins are considered grave also. These sins not only offend God, but men as well. Thus these four sins are called “the sins that cry to heaven for vengeance” and are likewise mortal sins. These grave sins are:
Finally, the capital sins are also considered grave matter. These sins are vices and are defined as contrary to the Christian virtues of holiness. They are pride, avarice, envy, wrath, lust, gluttony, and sloth (acedia).
Note from the author: For those of you who do not understand why these particular sins are of grave matter, I would suggest that you refer to the Summa Theologiae of St. Thomas Aquinas. He does an excellent job of explaining why these sins are of grave matter, and also explores the counter-arguments and objections that some people have regarding these grave sins.
A thorough listing and description of grave sins:
The First Commandment, “You shall Worship the Lord Your God and him only Shall You Serve”
The Second Commandment, “You shall not take the name of the Lord your God in vain”
The Third Commandment, “Remember the sabbath day, to keep it holy”
The Fifth Commandment, “You shall not kill”
The Sixth Commandment, “You shall not commit adultery”
The Eighth Commandment—”You shall not bear false witness against your neighbors”
The Ninth Commandment—”You shall not covet…your neighbor’s wife”
The Tenth Commandment—”You shall not covet…anything that is your neighbors”
Offenses Against Faith
Offenses Against Hope
Offenses Against Charity
Of course we must realize that this is certainly not a complete list of sins. The sins that are listed above are those of grave matter that can become mortal sins if they are done willfully and with full knowledge of their nature. Other sins are of venial nature, and are less grave than the ones listed above.
What is venial sin?
As stated before, venial sin is a sin of lesser matter than grave sin. It can also be a sin of grave matter in which the sinner did not fully consent to the sin or did not have knowledge that his actions where sinful. Venial sins will not destroy grace in the soul, and will not directly cause a person who dies in the state of venial sin to lose the promise of heaven. Yet, venial sin weakens a person’s will to avoid evil and thus may indirectly lead to mortal sin. Regardless, all sin is an offense against God and should be avoided.
All sins can be forgiven
A person who repents of their sin, intends to live a new life of grace, and receives the Sacrament of Reconciliation will be forgiven of all their sins (mortal sins in particular must be confessed in the Sacrament). Our sins can be forgiven, because Jesus Christ paid for the price of human sin by dying on the cross for the redemption of humanity. Jesus Christ, true man and true God, was the perfect sacrifice for human sin and as a result saved those who are baptized, repent and believe in him.
Because a baptized Christian can still sin, Christ instituted the Sacrament of Reconciliation for the forgiveness of our sins. Jesus gave the power to forgive sins in his name to the Church. He told his apostles, “Receive the Holy Spirit. Whose sins you forgive are forgiven them, and whose sins you retain are retained” (John 20:22–23). This means that the apostles and their successors, the priests and bishops of the Catholic Church, can forgive sins in Jesus’ name.
It is vitally important that Catholics confess sins on a regular basis, especially if we are in the state of mortal sin. A person who dies in mortal sin cannot enter the kingdom of heaven and is doomed to eternal suffering in hell. Even when we have not committed mortal sin, we are still obliged to confess our sins at least once a year. Christ, in perfect love, laid down his life so that we may be forgiven of our sins. The sacrifice of the cross should not be neglected or taken for granted. Jesus died for the life of the world and is thus the light of the world. “He that followeth me, walketh not in darkness, but shall have the light of life” (John 8:12)