What does Proverbs 2:15 mean?

Prior verses extolled the value of justice, which is a proper application of wisdom and understanding. Verses 14 and 15 conclude this section on justice with the culmination of the description of an evil person. Here the Proverb describes crooked paths and devious ways—the opposite of justice. The modern term which comes to mind in describing this type of person is manipulative. This person delights and rejoices in evil, as stated in verse 14, and will stop at nothing to see that evil realized. He deliberately twists his path to meet his own desires. He perverts the truth to conform to his devious ways.

A powerful example of this is found in the Serpent's questions to Eve in Genesis chapter 3. First, the Serpent casts doubt on what God actually did or did not command. Then, he draws the woman into thinking about the fairness of God's command. Then he flatly calls God a liar, questioning God's character and motives. Nothing could be more crooked or devious.