Hearts will Fear Judgment

Hosea 10:8 
Also the high places of Aven, the sin of Israel, Shall be destroyed.  The thorn and thistle shall grow on their altars; They shall say to the mountains, “Cover us!” And to the hills, “Fall on us!”

- Luke 23:30.  "Then they will begin ‘to say to the mountains, “Fall on us!” and to the hills, “Cover us!” ’"

- Revelation 6:15-17  And the kings of the earth, the great men, the rich men, the commanders, the mighty men, every slave and every free man, hid themselves in the caves and in the rocks of the mountains, 16 and said to the mountains and rocks, “Fall on us and hide us from the face of Him who sits on the throne and from the wrath of the Lamb! 17 For the great day of His wrath has come, and who is able to stand?”"

When God justly deals with our sin at the end of time, men will panic and cry out to hide from His anger against sin, even trying to hide underground.  Nobody can hide or stand in their own perceived goodness; they will only know then they have none apart from that given by Christ.  He died to take our just punishment, and is the only way to be saved from God's just anger for and end of sin.