Conditions of the "heart" seem to run through the proverbs in Proverbs 15:11-15.
Verse 11--Sheol and Abaddon lie open before the Lord,
how much more human hearts!
Verse 12--Scoffers do not like to be rebuked;
they will not go to the wise.
Verse 13--A glad heart makes a cheerful countenance,
but by sorrow of heart the spirit is broken.
Verse 14--The mind of one who has understanding seeks knowledge,
but the mouths of fools feed on folly.
Verse 15--All the days of the poor are hard,
but a cheerful heart has a continual feast.
Important practical lessons for daily godly living in these verses include the following.
1. The Bible consistently reminds human beings that God sees and scrutinizes the inner desires, secret motives, and repressed plans of the heart. See Proverbs 15:3; 17:3; 22:12; Hebrews 4:13; etc.
2. Commenting on Proverbs 15:12, Kenneth Aitken writes [The Daily Study Bible Series: Proverbs, p. 111]: "A scoffer will never try to see, far less respect, someone else's point of view. He is always right and the other fellow is always wrong. . . He never has a positive or a good word to say about anybody or anything; but he is always quick to let drop the cynical comment and snide remark to pour cold ater on what anyone else says."
3. Everyone likes to be around a person with a "glad" or "cheerful" heart, a person who has a positive and optimistic outlook on life, who consistently sees the good in others and finds things in which to rejoice, who has a contagious smile. What a contrast to one who is always down in the dumps, looks for things about which to complain, and who dampens the spirits of all those around him or her!
4. A truly wise person knows she or he does not know everything, and does not know anything perfectly; so a wise person is always open to learning new things or learning old things more accurately, and thus to changing her or his mind and ways of life. By contrast, a fool is deeply rooted in his or her beliefs and outlook on life, and would never consider the possibility that he or she needed to change his or her understandings or way of life.