This week we come to Question 12 of the New City Catechism, found in Part 1 (questions 1-20), which focuses on God, creation and the fall, and the law.
Question 12: What does God require in the ninth and tenth commandments?
Answer: Ninth, that we do not lie or deceive, but speak the truth in love. Tenth, that we are content, not envying anyone or resenting what God has given them or us.
The ninth commandment forbids the bearing of false witness, or the use of our words in a deceitful manner to the harm of others and for our own benefit (Exod. 20:16). God despises perjury and deception. The Word of God is truth itself (John 17:17). It does not merely correspond to an external standard of truth, but is itself the standard the determines what is and is not true. Scripture bears witness to the fact that God never lies (Titus 1:2). Indeed, it is impossible for God to lie (Heb. 6:18). Because God is a God of truth, he commands us to imitate him by speaking what is true instead of manipulating others with our words to our own advantage.
In the Sermon on the Mount, Jesus warned against swearing oaths (Matt. 5:33-37), not only because the common Jewish practices of his day regarding oaths were quite arbitrary and ridiculous (see Matt. 23:16-22), but also because his disciples should have no need to swear. Their words should be trustworthy because they are known as honest people. As Christians, may we be known for honesty, transparency, and genuineness rather than lies and manipulation.
Suggested passage for family or personal reading: Matthew 5:33-37. Why shouldn’t Christians make it a practice to swear oaths? Are there any occasions when it would be okay to swear, such as in a courtroom? What is Jesus’ main point about how we should speak with others?