Catholic Teaching on Sin and Forgiveness: A Simple Breakdown

Diana Rivas
May 5
4 min read

Catholic Teaching on Sin and Forgiveness: A Clear Explanation

If you’ve ever wondered what sin actually is, what makes one sin more serious than another, or how to be forgiven, this guide is for you. Whether you’re coming back to the faith or learning it deeply for the first time, here’s a simple and clear explanation.

What Is Sin?

Sin is when we knowingly and freely choose to do something that goes against God’s will. It’s not just about breaking a rule—it’s about damaging or breaking our relationship with God and with others. The Catholic Church teaches that there are two main types of sin: venial and mortal.

1. Venial Sin (Less Serious)

These are smaller sins that are still wrong but don’t completely separate us from God. They harm our relationship with Him, but do not destroy it.

What makes a sin venial:

The action is not seriously wrong in itself.
You may not have realized it was sinful.
You didn’t fully choose it with deliberate intent.

Examples of venial sins:

Being impatient or rude to someone
Telling a small lie to avoid embarrassment
Being lazy or failing to pray out of distraction
Saying something unkind in the moment

How venial sins are forgiven:

Through sincere personal prayer and asking God for forgiveness
By attending Mass and receiving Holy Communion with reverence
Through acts of love, kindness, and charity
By confessing them during the Sacrament of Reconciliation (optional but helpful)

While venial sins don’t cut us off from God completely, they can weaken our spiritual life if we continue in them without turning back to Him.

2. Mortal Sin (Very Serious)

Mortal sin is a serious offense that completely breaks our relationship with God. It is called “mortal” because it causes the spiritual death of the soul—it removes sanctifying grace from the heart.

For a sin to be mortal, three things must all be true:

Grave Matter – The act itself is seriously wrong.
Full Knowledge – You knew it was wrong.
Full Consent – You freely and deliberately chose to do it.

Examples of mortal sins:

Choosing to skip Sunday Mass without a valid reason
Committing adultery or engaging in sexual activity outside of marriage
Using pornography or engaging in lustful actions
Stealing something valuable
Harming another person seriously or choosing not to forgive
Having or supporting an abortion
Speaking or acting with hatred or serious disrespect toward God

Why this is so serious:Because mortal sin involves a full rejection of God’s love and grace. It separates us from Him, not because He stops loving us, but because we turn our hearts away from Him.

How to Be Forgiven

1. Through the Sacrament of Confession (Reconciliation)

This is the ordinary and most complete way to be forgiven—especially for mortal sins.

What happens in Confession:

You examine your conscience (reflect honestly on your sins).
You feel true sorrow (contrition) for offending God.
You confess your sins out loud to a Catholic priest.
The priest gives you a penance (prayer or action to help you grow).
The priest prays the words of absolution, and your sins are completely forgiven by God.

Why go to a priest?Because Jesus gave the apostles the authority to forgive sins (John 20:23), and that power continues today in the Church through priests.

Confession is not about shame. It’s about healing. The priest is not there to judge but to help you return to God with a clean heart.

2. Perfect Contrition (Outside of Confession in Emergency)

If someone commits a mortal sin but cannot get to a priest (for example, in a life-or-death situation), God can still forgive them directly if:

They are truly sorry out of love for God (not just fear of punishment).
They intend to go to Confession as soon as they are able.

This is the exception, not the norm. The Church teaches that confession is still required afterward when possible.

Forgiveness for Venial Sins Without Confession

You don’t need to go to confession every time you commit a venial sin, but it is encouraged. Venial sins can also be forgiven by:

Saying a sincere Act of Contrition
Participating in the Mass and receiving Communion reverently
Doing good works, making sacrifices, and helping others with love

Quick Summary Chart

Type of Sin	Description	Examples	How to Be Forgiven
Venial	Less serious offense that harms but does not break relationship with God	Impatience, white lies, gossip, laziness	Prayer, Mass, good works, optional confession
Mortal	Serious offense that breaks relationship with God entirely	Missing Mass, sexual sin, serious theft, hatred	Requires confession (ordinary way); perfect contrition in emergencies

Final Words

Sin matters because it affects our relationship with God. But the good news is that God’s mercy is always available. No matter how far you’ve gone, you are never beyond His forgiveness.

The Church doesn’t teach this to scare or shame people, it teaches this to help us live in freedom, truth, and grace. Confession is one of the greatest gifts we have. It’s where we meet Christ’s mercy face-to-face, hear the words “You are forgiven,” and begin again.