Why do we need additional light by which to see in life? Why is it that we need to be reproved and disciplined so that we choose life? The answer to these questions and to the reason the Bible spends so much time warning us about sin, is found in the worldview of the Bible when it comes to the basic nature of man. The Bible teaches that man is fallen and sinful. Our basic nature is to turn from God and His ways. If left to ourselves, we will NOT choose life. If left to ourselves, we will by the very evil in our nature, go in a direction that is contrary to God's way. That is why we need the light of God's Word to light our way. That is why we need reproofs and corrections to move us into the path of God's commandments.
Here, after making that clear, the writer of Proverbs then reminds us that one of the ways that we will choose to our detriment, is the way of the evil woman. The word evil here is the Hebrew "ra" which means an active, pernicious evil. This is an evil that cannot rest unless it is acting out evil - and encouraging others to do the same. The woman who is abandoning her vows to her husband - and encouraging other men to do the same - is an evil woman. But unless you are wise, you will not detect her as such. The father who is speaking here warns his son to turn to wisdom and the commandments and reproofs of God, so that he will not be led astray by the smooth tongue of this adulteress. Her smooth tongue is her weapon of choice. She uses it to flatter a man and use his natural tendency toward pride and a bloated ego as a trap. That is why we are warned against her smooth, flattering tongue. And it is also why we need God's commandments to direct us where our egos and our sinful nature will not. Finally, it is why we also need the Word of God to rebuke and reprove us when we begin to make unwise decisions concerning sexuality and the kind of company we keep with the opposite sex.