The committed fool (kesil,lutz, and nabal) hates correction because it challenges the fortress of foolish speculations that undergird his identity. He has exchanged the truth of God for a lie, and God has given him over to his lusts. These lusts largely define who he is. Correction of this unhappy soul is rarely effective via the front door, where the Christian barges it down with the self-righteous zeal of Phineas, offering little empathy for the imprisoned soul shackled by lusts. In order to get a fool to reassess his "wisdom in his own eyes," the fool needs to hear the testimony of the believer whose previous foolishness he can relate to. It's hard to be defensive about someone else's idolatry, so if the Christian story resonates with the fool's story, the fool might be open to similar correction. Take the "I'm right/you're wrong" narrative off the table by identifying and sympathizing with the plight of the fool. If not for the grace of God, we're all incorrigible fools.
When Fools Test Your True Identity
This episode, focusing on Proverbs 26:4-5, admonishes believers to engage fools without being carnal. Fools are naturally defensive in regards to correction, since their identity is virtually synonymous with the lusts they pursue. Potential correction is threatening to their identity. The identity of Christians, by contrast, is Christ Himself, so believers SHOULD more easily abandon behaviors upon correction, because they are not reflective of their true holy identity. That being said, the Christian's old fleshly nature is often provoked by fools through personal attacks and verbal abuse designed to draw us into fleshly combat. Upon encountering fools, we need to find rest and peace in our secure positional identity in Christ, acknowledging that fools are insecure by nature, depending as they are on the world and its lusts that are passing away. (1 John 2:17)
Correct the Fool without Being Foolish
Proverbs 26:4-5 initially appears to give contradictory advice: "DO NOT ANSWER a fool according to his folly, or you will also be like him. ANSWER a fool according to his folly, that he not be wise in his own eyes." The keys to properly interpreting the apparently conflicting advice are the descriptions qualifying the imperative. The objective in the first case is engaging a fool without stooping to his level, using abusive language, character assassination, deflecting and blame-shifting. The goal should be rather narrowly correcting the fool over the issue in dispute, addressing raw facts without being abusive or judgmental of the fool. Of course the fool might still blow you off, but at least you're not communicating like the fool, according to his folly. And methodically sticking to the issue without being disrespectful is potentially corrective. The fool can no longer easily be right in his own eyes. The real issue then in these verses is how we converse with a fool, who would provoke a response in us that is verbally abusive, and abuse returned discredits whatever wisdom we might provide.