The Eighth Commandment calls us to live in truth, speak with honesty, and reject all forms of deception. At its heart, it safeguards relationships, justice, and trust in both personal and public life. Without truth, human society collapses into suspicion and manipulation. God Himself is Truth (cf. John 14:6), and those who follow Him are called to reflect His truth in word and deed.

1. What This Commandment Forbids

The Catechism (CCC 2464–2513) expands the scope of this commandment beyond the courtroom:

• False witness and perjury – Lying under oath, distorting truth in legal or social contexts.

• Lies in daily life – Any deliberate falsehood, whether big or small (“white lies” included).

• Slander and detraction – Damaging another’s reputation by lies or revealing truths unnecessarily.

• Gossip and rumours – Spreading unverified or harmful information.

• Flattery, boasting, or hypocrisy – Using words to manipulate or deceive.

• Media misuse – Spreading misinformation, fake news, or propaganda.

2. Positive Demands of the Commandment

It is not just about avoiding lies but also about living truthfully:

• Witness to Christ – Jesus is “the Way, the Truth, and the Life” (John 14:6). To follow Him is to walk in truth.

• Defending justice – Speaking truth where silence or deceit would harm others.

• Protecting reputations – Practicing charity by speaking well of others and keeping confidences.

• Integrity and transparency – Living so that one’s words match one’s actions.

• Evangelisation – Truth builds credibility in preaching the Gospel.

3. Real-Life Applications

• At home: speaking honestly within the family, avoiding excuses or exaggerations.

• At school or work: refusing plagiarism, fraud, or cover-ups.

• In society: challenging corruption, misinformation, and manipulation in media or politics.

• Online: resisting gossip, fake news, or posting misleading images and stories.

• In faith: bearing witness to Christ even when it is uncomfortable or costly.

4. Why Truth Matters

• Truth builds trust – Without it, friendships, marriages, and communities crumble.

• Truth reflects God – To lie is to act against His very nature.

• Truth sets us free – Jesus promised, “The truth will make you free” (John 8:32).

• Truth saves – In the end, it is the truthful witness to Christ that leads to eternal life.

5. Living the Commandment Today

• Examine your conscience: Do my words reflect honesty and charity?

• Guard your speech: Speak only what builds up, not what tears down.

• Correct falsehoods: Stand up when lies are told, even if it is uncomfortable.

• Witness with courage: In a world full of spin, propaganda, and half-truths, Christians are called to be people of truth.

Conclusion

The Eighth Commandment is more than a rule against lying—it is a call to live as children of God, who is Truth itself. Every lie wounds relationships and society, while every act of truth-telling builds the Kingdom of God.

To follow this commandment is to follow Christ Himself, who lived and died bearing witness to the truth.

“Let what you say be simply ‘Yes’ or ‘No’; anything more than this comes from the evil one.” (Matthew 5:37)