Jeremiah 17:9

17:9 The human mind is more deceitful than anything else.

It is incurably bad. Who can understand it?

Matthew 26:33-35

26:33 Peter said to him, “If they all fall away because of you, I will never fall away!” 26:34 Jesus said to him, “I tell you the truth, on this night, before the rooster crows, you will deny me three times.” 26:35 Peter said to him, “Even if I must die with you, I will never deny you.” And all the disciples said the same thing.