As we try to grow in holiness through the reception of the Sacrament of Penance, it is helpful to know what we are confessing. There are two types of sins that we can commit: mortal and venial. While some may think that this language is too old-fashioned, it actually comes straight from scripture and is relevant to our spiritual life. Let’s take a look at what the Apostle John wrote about mortal and venial sin.
“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).
The words “mortal” and “deadly” are synonyms. There are certain sins that we can commit that are deadly for our spiritual life. This means that when we commit a mortal sin, the divine life of God which was ignited in our soul through baptism is extinguished. The Church teaches that someone who dies in the state of mortal sin, that is, without ever repenting of that sin, has chosen to go to hell through their own free will. Most of the sins that we commit are considered “venial,” which means small or slight.
To commit a mortal sin, three conditions must be fulfilled. First, the action done must be objectively very bad. It’s impossible to compile an exact list of mortal sins, but it’s commonly understood that the Ten Commandments are examples of grave or serious sins. St. Paul often lists sins in his letters, such as in his letter to the Galatians. “Now the works of the flesh are plain: fornication, impurity, licentiousness, idolatry, sorcery, enmity, strife, jealousy, anger, selfishness, dissension, factions, envy, drunkenness, carousing, and the like. I warn you, as I warned you before, that those who do such things shall not inherit the Kingdom of God” (Galatians 5:19-21.) While some mortal sins are obvious, like murder and adultery, some are actually not universally known. One example of this is that missing Mass on Sunday is a very serious sin for Catholics which could exclude them from the Kingdom of Heaven. Of course, during Covid time, most bishops have lifted the obligation to attend Mass. However, without a good reason such as sickness, Catholics are normally obligated to attend Mass on Sundays and Holy Days of Obligation. To miss Mass on Sunday is to directly disobey the Third Commandment: Keep holy the Lord’s Day.
The second condition for something to be a mortal sin is that the person must have knowledge that the sin is serious. There are many things that we should know are wrong because of our instinct as human beings. However, some things are not so clearly understood or universally known. The example I used in the above paragraph is once again applicable. The unfortunate fact is that some Catholics do not know that they are required to attend Mass on Sunday. If someone truly does not understand this, through no fault of their own, then missing Mass would not be a mortal sin.
The third condition for an action to be a mortal sin is that it be completed with the full consent of someone’s will. Sometimes through addictions or other outside influences, someone’s ability to consent to an action can be substantially lessened, and thus would not be a mortal sin.
The only regular way for mortal sins to be forgiven is through the reception of the Sacrament of Penance. If we have committed a mortal sin, we should never receive Communion without first confessing this sin in the sacrament of Penance. This is to ensure that we receive the Eucharist worthily and avoid causing more spiritual harm to ourselves.
We should never despair of God’s mercy, no matter how often we may fall into sin. He desires so much to have us reconciled to him. The point of discussing the reality of sin is not to make us despair or be discouraged but to help us to grow more intentionally in the spiritual life. Let us run into the Father’s open arms of love and return to him with our whole hearts through the sacrament of Penance!