Proverbs 14:13

Even in laughter the heart is sorrowful; and the end of that mirth is heaviness.

In the Proverbs 12 to 15 reading the verse teaches the value of sincerity. Even in laughter, smiling, and mirth the heart can remain sorrowful, so outward merriment does not always reveal inward feelings or happiness. Those whose lives are on the way to death may laugh outwardly while inwardly burdened with sorrow. Carnal pleasures and sensual delight bring no lasting joy: while they last a person may sing, but when their reckoning comes the cheer ends in heaviness.

People who seem enviable may carry private pain, and their true condition would awaken pity if it were known. Every heart carries its own hidden sorrow even under outward merriment, a homesick corner caused by such things as a wayward son or daughter, cruel poverty, disappointed hopes and ambitions, or the haunting fear that a past hidden crime will be discovered robbing the soul of peace. People may act brave and struggle hard to hide this grief, yet times come in every life when hunger for human love and sympathy is deeply felt. The verse warns against judging the heart by outward merriment, for eyes that seem bright with laughter may be struggling to hold back tears.

The end of mirth is heaviness, sadness, and misery, and a laugh that ends in bitter tears is not a lasting delight. Worldly merriment cannot remove the heart's heaviness. This is contrasted with the Christian's cheerfulness, which rests on hope in God and can remain even in difficult circumstances. Since sorrow and tears can remain in the heart even while smiling, the verse calls for smiling cheerfully despite inward tears.