Paul does not promise that grief will lift quickly. He names God as the Father of mercies and the God of all comfort, who meets his people in real affliction and then sends that same comfort through them to others.

Proverbs 17:22 observes that an inner condition of the heart has real, felt consequences: cheerfulness does good like medicine, and a crushed spirit drains a person. It is wisdom about how God made us, not a formula for healing or a command to be funny.