---
title: "Why does telling the truth matter so much?"
url: "https://seekabove.com/answers/what-is-the-eighth-commandment"
description: "The Eighth Commandment — “you shall not bear false witness against your neighbour” — calls us to live in the truth: to be honest, to speak truthfully, and to guard others’ good name and reputation. I…"
published: "2026-06-06"
updated: "2026-06-10"
category: "Christian Life"
scripture: ["Exodus 20:16", "Ephesians 4:25", "Proverbs 12:22", "John 8:32", "Colossians 3:9-10"]
catechism: "CCC 2464, 2468, 2475–2477, 2479, 2482–2483, 2487–2488"
---

# Why does telling the truth matter so much?

## Short answer

The Eighth Commandment — "you shall not bear false witness against your neighbour" —
calls us to live in the truth: to be honest, to speak truthfully, and to guard others'
good name and reputation. It forbids lying, false accusation, gossip that tears people
down, and rash judgement, and it requires us to repair the harm when we've damaged
someone's reputation.

## Full explanation

Originally this commandment guarded against false testimony in court — lying that could
cost an innocent person their freedom or life. But its principle is much wider: it
protects the **truth** in all our dealings with one another, because human community runs
on trust, and trust runs on truthfulness. As Scripture says, the truth sets us free, and
Jesus himself *is* "the truth."

The most obvious violation is **lying** — speaking or acting against the truth in order
to lead someone into error. The Church takes lying seriously because it
corrupts the very purpose of speech (to communicate truth) and because it injures trust.
That said, the gravity varies enormously with the harm done — a small social fib and a lie
that destroys someone's life are not the same weight, even though both fall short of the
truth we're called to.

But the commandment reaches well beyond outright lies, into the everyday ways we damage
people with our words:

- **Rash judgement** — assuming the worst about someone without good grounds.
- **Detraction** — revealing someone's real faults to people who have no need to know,
  damaging their reputation. (Notice: this is wrong even when what you say is *true*.)
- **Calumny (slander)** — saying false things that harm someone's good name.
- **Gossip** — the casual trade in others' failings that quietly corrodes whole
  communities.

Our culture treats gossip as harmless entertainment; the Church treats a person's good
name as something precious that we have no right to wreck. And because reputation is real,
the commandment carries a duty of **reparation**: if you've spread lies or unjustly
damaged someone's name, justice requires you to set the record straight as far as you can.

The commandment also asks us to honour the truth wisely. Telling the truth doesn't mean
blurting out everything we know to anyone who asks — we must respect **privacy** and
confidences (a doctor, a priest in confession, a friend's secret), and use charity and
discretion about what is shared and with whom. Truthfulness and love work together: we're
called to speak the truth, and to speak it *in love*.

## Why this matters

Words build people up or tear them down, and most of us sin more often with our tongues
than with anything else — through the half-truth, the cutting remark, the juicy bit of
gossip. This commandment forms us into people who can be *believed* and who can be
*trusted with others' reputations*. A community where people tell the truth and guard each
other's good name is a community where trust, and therefore love, can actually grow.

## Common misunderstanding

One misunderstanding is that only outright lies break this commandment, so gossip and
running people down "behind their back" don't count — especially if it's true. But the
Church names detraction (revealing true faults without need) and gossip as real wrongs
against a person's good name. The opposite mistake turns "always tell the truth" into a
duty to disclose everything; the commandment also requires discretion, confidentiality,
and respect for privacy.

## Scripture connections

- **Exodus 20:16** — "you shall not bear false witness against your neighbour."
- **Ephesians 4:25** — "putting away falsehood, let each of you speak the truth."
- **Proverbs 12:22** — "lying lips are an abomination to the Lord."
- **John 8:32** — "the truth will make you free," the freedom truthfulness brings.
- **Colossians 3:9-10** — "do not lie to one another," part of putting on the new self.

## Church teaching references

- CCC 2464, 2468, 2475, 2476, 2477, 2479, 2482, 2483, 2487, 2488
- The Catechism treats the Eighth Commandment as living in the truth — against lying,
  detraction, calumny, and rash judgement, with duties of reparation and respect for
  privacy.

## Reflection question

Think back over the last few days of your conversations — was there a moment of gossip, a
shaded truth, or a quick judgement of someone, and is there a good name you should help
repair?