What does the Bible say about sadness among believers?

In Luke 24:17, Jesus questions two of His followers on the road to Emmaus, asking, 'What manner of communications are these that ye have one to another as ye walk and are sad?' This scripture illustrates that even believers can experience sadness. However, it's important to note that while sadness is a natural human emotion, it should not overshadow the joy of our salvation. The Lord recognizes our burdens and asks us to cast our cares upon Him, reminding us of His constant presence and promise to not forsake us (Matthew 28:20).