Is Lying A Mortal Sin?

It seems like such an obvious fact that lying is a sin. We’ve grown up being taught by our parents, teachers and other authorities never to lie. 

But the morality of lying is, surprisingly, a subject of debate among philosophical and religious experts. That’s because there are different kinds of lies. 

Not everyone who lies does it with the intention of causing malicious harm. Jocose lies are those that are made in jest or amusement. 

There are also officious lies that are told to benefit someone. Then there are injurious lies that are told with malicious intent and directly cause harm or injury. 

Does that mean that one type of lie is better or worse than another? Is lying a mortal sin?

What Does the Catholic Church Say About Lying?

What Does the Catholic Church Say About Lying

The view in Catholicism, and Christianity in general, is that any sort of lying is a sin. The Bible is very emphatic on the truth. 

Jesus refers to himself as the truth in John 14:6. 

Jesus answered, “I am the way and the truth and the life. No one comes to the Father except through me.

The Bible is also insistent on the seriousness of dishonesty. The eighth commandment states, “You shall not bear false witness against your neighbor.”

Here is Proverbs 12:22.

The LORD detests lying lips, but he delights in people who are trustworthy.

And here’s Colossians 3:9. 

Do not lie to each other, since you have taken off your old self with its practices.

The Catechism of the Catholic Church says the following regarding lying (Para 2485): 

By its very nature, lying is to be condemned. It is a profanation of speech, whereas the purpose of speech is to communicate known truth to others. 

Telling the truth, no matter the cost, is important. Lying, whether it’s to amuse yourself, get out of trouble (white lies), or to cause harm, is a sin. 

One reason to avoid lying of any kind is that it’s easy for it to become a habit. Sometimes we do it without thinking. 

For example, when you gossip about a friend or neighbor, you are likely telling some falsehoods. The same applies to boasting; you are likely over representing your abilities or achievements. The automatic white lies we tell to our partners, bosses, and even kids often become second nature. 

And you may think that a certain lie is harmless, but often it’s easy to cause unintended harm.

The bottom line is that lying is a sin. But what type of sin is it, mortal or venial? 

Is Lying Always a Mortal Sin?

Is lying always a mortal sin

No, lying is not always a mortal sin. 

A mortal sin is one where you commit a grave sin with full knowledge of its gravity and consequences. The type of lying that falls under this category is injurious lying. 

When you lie knowing full well that your dishonesty will hurt someone, or perhaps with the intention of hurting someone, that’s a mortal sin. 

Some examples include lying when under oath, telling lies about your neighbor, or knowingly lying to a police officer

Forgiveness for mortal sins requires confession to a priest and deep contrition. 

But most of the lies we tell, often without thinking, are venial sins. These are less serious sinful acts, done without intention of causing harm and without knowing their consequences. 

Most white lies are venial sins. For example, lying to your college professor why you are late for class, or telling your partner that you’ve taken out the trash and you haven’t. 

Venial sins still injure your friendship to God, but they do not sever it. You can go to confession or seek forgiveness privately.  

To summarise, here’s what the Catechism of the Catholic Church says on the gravity of lying (Para 2484). 

The gravity of a lie is measured against the nature of the truth it deforms, the circumstances, the intentions of the one who lies, and the harm suffered by its victims. If a lie in itself only constitutes a venial sin, it becomes mortal when it does grave injury to the virtues of justice and charity.

Is Telling a White Lie a Mortal Sin?

White lies are usually not mortal sins. They are considered venial sins since you do not intend to cause harm and don’t foresee any grave consequences. 

That said, a white lie can be a mortal sin in certain circumstances. For example, a white lie under oath is no longer a venial sin. That’s a mortal sin since it’s perjury. 

Also, if you tell a white lie but you know very well that it’ll have grave consequences (e.g. someone innocent going to prison, or tainting the reputation of someone), that’s also a mortal sin. In fact, we can’t call that a white lie. It’s an injurious lie. 

Read also: Is It A Sin To Kill In Self Defense?

When is Lying Permissible? 

Despite the emphatic Biblical and Catholic instructions and teachings not to lie, most of us can imagine a situation where telling a lie would surely be permissible, even necessary.  

Think of the good people who hid Jews in their homes from the Nazis. 

There’s a lot of debate on where there are circumstances where it’s alright to lie, even though it’s a sin. 

Some experts say that you can lie, while others recommend taking a roundabout way by not sharing the truth but without lying. 

For example, you might answer Nazis asking if there are Jews in the house by saying, “I have not invited anyone into my home.”

Most of us, however, will almost certainly never face a situation where lying can potentially save a life. So instead of trying to justify lying in some situations, avoid lying at all. 

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