Did you know God commands us to be joyful?

Rejoice in the Lord always. I will say it again: Rejoice! (Philippians 4:4 NIV)

Rejoice always, pray continually, give thanks in all circumstances; for this is God’s will for you in Christ Jesus. (1 Thessalonians 5:16-18 NIV)

sorrowful, yet always rejoicing; poor, yet making many rich; having nothing, and yet possessing everything. (2 Corinthians 6:10 NIV)

There I will go to the altar of God, to God—the source of all my joy.
(Psalms 43:4 NLT)