"We are nowhere forbidden to laugh, or to be satisfied with food, or to annex new possessions to those already enjoyed by ourselves or our ancestors, or to be delighted with music, or to drink wine." John Calvin
"Joy is the serious business of heaven." C.S. Lewis
"Blessed are you poor... Blessed are you who hunger... Blessed are you who weep... Blessed are you when men hate you... exclude you... revile you... For the Son of Man's sake. Rejoice in that day and leap for joy! For indeed your reward is great in heaven..." Luke 6:20-23
Blessed means happy. Jesus commands, demands our happiness, our joy. Matthew 5:12 "Rejoice and be exceedingly glad for great is your reward in heaven...". He wants us to think about heavenly rewards, because He Himself mentions it several times. He reminds us of it. Keep it on your mind. This is the reason why you can go through mourning, poverty, hunger, persecution because Jesus reminds us of heavenly reward.
It must be absolutely fantastic, marvelous- for that hope to sustain and produce joy in times of severe trial. "I rejoice in my sufferings for you..." Colossians 1:24. "...who for the joy set before Him endured the cross..." Hebrews 12:2. "Consider it pure joy whenever you face trials..." James 1:2. "Blessed is the man who perseveres under trial, because when he has stood the test, he will receive the crown of life that God has promised to those who love Him." James 1:12
In what do we rejoice? In God's great mercy. He gave me new birth, He gave me a living hope. Because of Christ's resurrection, I have an inheritance that can never perish. I am shielded by God's power until He comes again.
"...rejoice in the hope of the glory of God... also rejoice in our sufferings..." Romans 5:2,3
For a moment lay aside your suffering , your worry, your sadness and list your blessings. I know when you are in physical pain or emotionally depressed this is easier said than done. So I pray for the Lord's mercy on you right now, that He will lift your spirits and ease your mind and help your pain to go away. In the powerful name of Jesus. Amen.