This sermon explores the causes of a heavy heart by examining biblical figures like Esau, David, Ahab, and Naomi who experienced rejection, regret, unfulfilled expectations, and loss. It identifies the primary remedy for such sorrow as receiving a good word from God's Word, particularly through Psalms and Proverbs. The preacher emphasizes that choosing joy and maintaining a merry heart acts as spiritual medicine that sustains the spirit and improves physical health. Believers are encouraged to reject negative influences and instead focus on the hope of eternity and God's providence. Ultimately, the message calls for an intentional choice to find gladness in Scripture rather than dwelling in despair.