The fool has said in his heart, “There is no God.” Anyone who fails to acknowledge God’s revelation is forced to be a fool. They are forced to be a fool because they can’t reason from a true premise. It’s impossible for them to do so. If they come up with proof (a premise), what makes them think that their proof (premise) is true? They might give proof (a premise) for their proof, but what makes them think that the proof of their proof is true? Well, they can try again and again, but they never find a true premise. Divine revelation is directly imparted by God. Acknowldging Him as the Holy Spirit guides, leads, and teaches is the only way to avoid being a fool.