The Ninth Commandment Heidelberg Catechism Lord's Day 43 112. What does the ninth Commandment require? That I bear false witness against no one, twist no one's words, be no backbiter or slanderer, join in condemning no one unheard or rashly; but that on pain of God's heavy wrath, I avoid all lying and deceit as the very works of the devil; and that in matters of judgment and justice and in all other affairs, I love, speak honestly, and confess the truth; also, insofar as I can, defend and promote my neighbor's good name. The sermon centers on the Ninth Commandment's call to uphold truth and reject all forms of deceit, emphasizing that lying—whether in speech, judgment, or self-deception—is rooted in the nature of the devil and contrary to God's character as the source of truth. It challenges the congregation to resist the cultural epidemic of gossip, slander, and hasty condemnation, urging careful discernment in media consumption and personal judgment, while highlighting the danger of self-deception and self-worship that distorts our perception of others. Christians are called not only to speak truth in justice and daily affairs but also to actively defend and promote their neighbor's good name, even when silence or discretion is required, reflecting Christ's call to bless rather than retaliate. The message underscores that true faithfulness to God involves a radical commitment to honesty, humility, and love, recognizing that our words should honor God and serve others, not fuel division or pride.