A Sound Heart Vs An Unsound Heart

Proverbs 14:30 King James Version (KJV) 30 A sound heart is the life of the flesh: but envy the rottenness of the bones. 

Mark 7:21-22 King James Version (KJV) 21 For from within, out of the heart of men, proceed evil thoughts, adulteries, fornications, murders, 22 Thefts, covetousness, wickedness, deceit, lasciviousness, an evil eye, blasphemy, pride, foolishness: 

Job 5:2 King James Version (KJV) 2 For wrath killeth the foolish man, and envy slayeth the silly one.