18 For the preaching of the cross is to them that perish foolishness; but unto us which are saved it is the power of God.
21 For after that in the wisdom of God the world by wisdom knew not God, it pleased God by the foolishness of preaching to save them that believe.
23 But we preach Christ crucified, unto the Jews a stumblingblock, and unto the Greeks foolishness;
25 Because the foolishness of God is wiser than men; and the weakness of God is stronger than men.
I Corinthians 2:14 KJV
But the natural man receiveth not the things of The Spirit Of God: for they are foolishness unto him: neither can he know them, because they are spiritually discerned.
I Corinthians 3:19 KJV
For the wisdom of this world is foolishness with God. For it is written, He taketh the wise in their own craftiness.