Jesus concludes his sermon on the plain (Luke 6:17-49) with two poignant illustrations: two trees and two foundations.
The fruit of a tree reveals the root — its nature (verses 43-45). It’s the same with hearts. The heart produces fruit after its true inner nature. Houses reinforce the point further. The foundation is what matters most, not the above ground appearance. Similar to fruit, which can help identify the nature of a person’s heart, the storm (verses 46-49) ultimately reveals the eternal stability of a life. The reason you often cannot tell the difference between true faith from a false profession is that the deep foundations of people’s lives are often hidden from view. The storm, that will eventually come upon every life, will reveal what sort of spiritual house we have.
The Sermon on the Plain is not meant to serve as an ethical manual as a pathway to God’s grace. It’s an ethical reversal to expose the foundation of our life and lead us to salvation in the gospel of God’s grace alone.