“But everyone who hears these sayings of Mine, and does not do them, will be like a foolish man who built his house on the sand: and the rain descended, the floods came, and the winds blew and beat on that house; and it fell. And great was its fall.” Matthew 7.26-27
The problems faced by the prudent are similar to those of a fool. The difference is that the prudent is unshakable, stands firm forever, whereas the fool cannot stand it and collapses. Worse: great is his fall. The ruin goes beyond physical loss, but concerns to the loss of his soul.