In Psalm 12, David laments about rampant wickedness in the world. It is clear from the opening line and the ending line of the psalm that David is not speaking about specific individuals. Instead, he means to speak hyperbolically about the godless society he finds himself in (vv. 1, 8). But rather than lamenting about their wicked acts, he characterizes the wicked according to their speech and contrasts their speech with God’s speech.
How are the wicked characterized according to their speech? They lie, flatter, and speak from “a double heart” (v. 2). They make “great boasts” (v. 3). Furthermore, “vileness is exalted” among them (v. 8). They place their own words above God’s authority by saying “our lips are with us” (v. 4) instead of saying, “God is with us.” Note how their three statements in verse 4 are both prideful and deceptive. Deceptiveness and pride are two key characteristics of the ungodly.
But David trusts in God’s judgment not only upon the wicked (v. 3) but in favor of those who are plundered by the wicked (v. 5). It is important to note David’s faith in the trustworthiness of God’s words. In contrast to the deceptiveness and pride in the speech of the wicked, God’s words are pure (v. 6). Whereas the wicked are unable to discern truth from lie, God will always be faithful to what he speaks. He will be faithful to punish the wicked and prosper his own in due time (v. 5).