We cannot speak about life in Christ or the moral life without acknowledging the reality of sin, our own sinfulness, and our need for God’s mercy. When the existence of sin is denied it can result in spiritual and psychological damage because it is ultimately a denial of the truth about ourselves. Admitting the reality of sin helps us to be truthful and opens us to the healing that comes from Christ’s redemptive act.
Sin is an offense against reason, truth, and right conscience; it is failure in genuine love for God and neighbor caused by a perverse attachment to certain goods. It wounds the nature of man and injures human solidar- ity. It has been defined as “an utterance, a deed, or a desire contrary to the eternal law.” (CCC, no. 1849, citing St. Augustine, Contra Faustum, no. 22)
Thus, by its very definition, sin is understood as an offense against God as well as neighbor and therefore wrong. Sins are evaluated according to their gravity or seriousness. We commit mortal sin when we consciously and freely choose to do something grave against the divine law and contrary to our final destiny.
There are three conditions for a sin to be a mortal sin: grave matter, full knowledge, and deliberate consent (freedom). Mortal sin destroys the loving relationship with God that we need for eternal happiness. If not repented, it results in a loss of love and God’s grace and merits eternal punishment in hell, that is, exclusion from the Kingdom of God and thus eternal death.
A venial sin is a departure from the moral order in a less serious matter. “All wrongdoing is sin, but there is sin that is not deadly” (1 Jn 5:17). Though venial sin does not completely destroy the love we need for eternal happiness, it weakens that love and impedes our progress in the practice of virtue and the moral good. Thus, over time, it can have serious consequences. “Deliberate and unrepented venial sin disposes us little by little to commit mortal sin” (CCC, no. 1863).
In considering sin we must always remember that God is rich in mercy. “Where sin increased, grace overflowed all the more” (Rom 5:20). God’s mercy is greater than sin. The very heart of the Gospel is the revelation of the mercy of God in Jesus Christ. “For God did not send his Son into the world to condemn the world, but that the world might be saved through him” (Jn 3:17).
To receive this mercy, we must be willing to admit our sinfulness. Sorrow for sin and confession of sin are signs of conversion of heart that open us to God’s mercy. Though we can judge a given offense to be the occasion for mortal sin, and thus an act of objective wrongdoing, we must always entrust the judgment of the person to the mercy and justice of God. This is because one person cannot know the extent of another individual’s knowledge and freedom, which are integral factors determining when an occasion for mortal sin becomes an actual sin for which we are morally responsible.
This article is an excerpt from the United States Catholic Catechism for Adults, copyright © 2006, United States Conference of Catholic Bishops. All rights reserved. Used with permission.