In David’s portrait of the ungodly in Psalm 12, he does not describe egregious sins of the flesh like homosexuality, adultery, or murder. Instead, he focuses upon the sins of the mouth, for it is out of the abundance of the heart that the mouth speaks; “a good man out of the good treasure of his heart brings forth good things, and an evil man out of the evil treasure brings forth evil things” (Matthew 12:34-35).
The mouth of the ungodly speaks idle words (Psalm 12:2). Vain and profane speech is sinful precisely because it uses profound and weighty words in trivial and meaningless ways. Idle words are weighty in the eyes of God (Matthew 12:36) because they arise from an ungodly heart.
The mouth of the ungodly speaks insincere words (Psalm 12:2). Flattery is a telltale sign of a divided heart. It is the perfume that a hypocrite uses to hide the stench of his evil heart and wicked motives. No amount of the lipstick of flattery can hide the pig of an insincere heart.
The mouth of the ungodly speaks arrogant words. They say, “With our tongues we will prevail; our lips are our own; who is lord over us?” (Psalm 12:4). No one, especially God, is going to have authority over their mouth. They will say what they want to say, whenever they want to say it, and how they wish to say it.
“If anyone among you thinks he is religious and does not bridle his tongue but deceives his own heart, this one’s religion is useless” (James 1:26).