The proverb in this verse combines two popular subjects in the book of Proverbs: fear of the LORD and wealth. The two at first seem opposed to each other. Upon closer examination, a lot about the two are revealed. First, fearing God is in degrees. One can have a little fear of God just as one can have faith as small as a mustard seed in God.
Second, great wealth does not guarantee peace of heart and mind. Great wealth often included turmoil, especially for those who do not have even a little fear of the LORD. The wealthy fool as defined in the Bible always worries about two things: losing what they have and not having enough. Since neither can be solved outside of fear and trust in God such people often have great inward trouble.
Third, fearing God does not guarantee great wealth all the time as some preach. If that were true then I would have to reconsider the lives of Jesus, the apostles. They were so poor they had to eat raw wheat allotted for the poor. And then the troubles of most of the prophets (Hebrews 11:36-38). Yet, I believe the truth stated in 3:9-10, “Honor the LORD with your wealth, with the first fruits of all your crops; then your barns will be filled to overflowing, and your vats will brim over with new wine.”