The ninth commandment forbids bearing false witness. The command alone should cause us to commit to speaking the truth. But God gives us at least four more good reasons to speak the truth:

1. God hates lying. Proverb 12:22 tells us that “lying lips are an abomination to the Lord.” God absolutely despises lying, and so we ought to speak the truth.

2. Habitual liars are lost. In Revelation 21:8, liars join murderers, sorcerers, and many other sinners in the lake of fire. A life characterized by lying denies a gospel transformation in one’s life. Liars need salvation.

3. Lying belongs to the old way of life. Colossians 3:9-10 reminds us that we have put off the old self with its sinful practices (including lying) and put on the new self. We have a new life in Christ, and we should act like it.

4. We follow the truth. Jesus is the truth (John 14:6). The Spirit is the Spirit of Truth (John 4:16-17). The Word is the Word of Truth (John 17:17). As we follow Jesus, the Holy Spirit, and God’s Word, we follow the truth. And if we follow the truth, our words should agree with the truth.