In the Sacrament of Penance, Catholics are obliged to confess serious (mortal) sins in kind and number since their last confession. If one is uncertain of the number, then an estimate is acceptable. Hence, one should always begin there: What are the more serious sins I have committed that may likely be mortal sins? No exact list of mortal sins can be given here since circumstances are important and because many sins have a range between serious and lighter matter. For example, gossip is usually not a mortal sin, but it might become so if reputations are ruined. Regarding lies, there are serious lies that cause harm and smaller lies that do less harm and are told merely to avoid awkward situations.
That said, we could generate something of a “hot list” of sins that tend to be more serious. There are sins against faith, such as idolatry and serious superstition. There is the sin of missing Mass without a serious reason, refusing the worship that is God’s due and refusing holy Communion, which is essential for us. There is invoking the name of God to curse rather than to bless, or making false oaths invoking God’s name. Serious disrespect to parents and lawful authority or the refusal to obey significant and just laws can become serious. Significant neglect of parents in their old age can also be serious.
Endangering the lives of others through reckless behavior can be serious as is the harboring of hateful and vengeful feelings, violent outbursts and other forms of destructive anger, whether verbal or physical. Abortion, or helping others to procure abortion, is gravely sinful, and so is the neglect to assist or warn others whose lives are endangered physically or spiritually. The willful viewing of pornography and the masturbation that often accompanies this, engaging in fornication, adultery and homosexual acts, are all mortal sins.
Stealing significant items or the intellectual or creative property of others can be mortal, as is damaging the goods or property of others in significant ways. Withholding the truth and lying can become serious, especially if the matter involves the reputation of others or important information they must have. Greed (coveting), too, can become serious when we act on it in ways that harm others significantly.
Circumstances will sometimes reduce culpability even in objectively serious matters. But these sorts of sins are a place to begin.
Another way to focus when going to confession when mortal sins are not a huge problem is to focus on a particular part of our life, such as family relationships, or on a particular sin, such as gluttony. Perhaps, too, we can look to sins of omission, not merely to what we have done. Attitudes such as fear, prejudice, pettiness, ingratitude and so forth can also be a particular focus to bring to the sacrament.
Msgr. Charles E. Pope has a Master of Arts in Moral Theology from Mount St. Mary’s University, Emmitsburg, Md. He was ordained to the priesthood on June 24, 1989, and is currently a pastor in Washington, D.C.