Psalm 95:7-9
Today, if you hear his voice, do not harden your hearts, as at Meribah, as on the day at Massah in the wilderness, when your fathers put me to the test and put me to the proof, though they had seen my work.

This generation has forgotten that the gospel message does not clean up and shine the outside of a person, rather it bores into the very heart and soul of a person and radically changes that person from the inside forever.
A.W. Tozer