House Built on Rock (Matt 7)What is the "analogy" in this scripture?

Analogy in Matthew 7: "House Built on Rock" The rock foundation is life built on FAITH. The house built on "Sand" are those things that are "fleeting" and not secure. How we "weather" the "challenges" in life depends on which "house" we have built. One built on Faith or one built on passing things in life.