Why are the words of Jesus described as revealing?

The words of Jesus serve as a mirror reflecting the spiritual condition of individuals. In John 6:64, He acknowledges that there are some who do not believe. His teachings expose the depths of human depravity and the necessity of divine intervention in drawing individuals to Him (John 6:65). The response to His teachings reveals what is truly in the heart; those who murmur against His hard sayings indicate an unregenerate heart, while those who acknowledge Him as the source of life reflect a heart transformed by God’s grace.