“Leave your naïve ways and live.” This seems to be the best reading (cp. Waltke, Proverbs; and Keil and Delitzsch give the same essence). The word “naïve” refers to the naïve person, the simple fool peti (#06612 פֶּ֫תִי). There are other ways to interpret the verse, however. The NIV (cp. ESV) reads “Leave your simple ways,” but the word “simple” is a noun, not an adjective, so the NASB, “Forsake your folly and live,” gives the same basic idea, while retaining the noun form of “simple.” However, it is less likely that the verse is telling us all to forsake our simple ways, and more likely that it is telling the naïve to forsake their ways. It is important to note that the rendition of the KJV is possible, “Forsake the foolish, and live,” but this rendition is not taken by most commentators as the more likely meaning. The context is Wisdom, who has built her house, set her table, slaughtered her animals, mixed her wine, and is now inviting people to her feast (Prov. 9:1-5). The simple, naïve, ignorant fools of the world are encouraged to leave their ignorance and dine with wisdom.
One thing this verse clearly does is make it known that people do not have to be, or remain, naïve or simple. Too often people think they cannot change, or think that change requires too much work to be worth it. God expects people to keep working on their knowledge and character and become truly godly people.
“on the road.” We all walk on a road in life. The godly are supposed to walk on the road of understanding, and make the effort to stay straight ahead on it. A person trying to leave naïve and foolish ways may find many reasons, including pleasures and pressures, to return to foolish ways, but Wisdom prods us to walk straight ahead on the road of understanding.