The Lord Jesus, in Matthew 5:22, warned His disciples against calling anyone, “Thou fool,” since we can only judge by outward acts. Yet the Scriptures, in general, and Christ, in particular (who could discern the inward character), do not hesitate to describe certain types of people as fools.
For example: “The fool hath said in his heart, There is no God” (Psalm 14:1). Anyone who tries to explain away all the innumerable evidences of God is a fool, the Bible says. So is anyone who rejects the teachings of Christ: “And every one that heareth these sayings of mine, and doeth them not, shall be likened unto a foolish man, which built his house upon the sand” (Matthew 7:26). In particular, one who lays up riches for himself is in this category. “But God said unto him, Thou fool, this night thy soul shall be required of thee: then whose shall those things be” (Luke 12:20). Christ rebuked the Pharisees as “fools and blind” (Matthew 23:17,19) because of their hypocrisy.
But perhaps the most foolish of all are those who proclaim themselves to be wise and then seek to rationalize their rejection of the Word of God. The Apostle Paul gravely warns against all such man-centered wisdom: “For the wisdom of this world is foolishness with God” (I Corinthians 3:19).
Such “wisdom” led to ancient paganism, and is now centered in evolutionary humanism. They “became vain in their imaginations, and their foolish heart was darkened. Professing themselves to be wise, they became fools, And . . . worshipped and served the creature more than the Creator” (Romans 1:21,22,25, as in the context of Romans 1:18–32). Such humanistic philosophy commonly masquerades as “science,” but God has warned: “I will destroy the wisdom of the wise” (I Corinthians 1:19). HMM