Nehemiah 8:10

Then Ezra said to them, “Go (your way), eat the rich festival food, drink the sweet drink, and send portions to him for whom nothing is prepared; for this day is holy to our Lord. And do not be worried, for the joy of the Lord is your strength and your stronghold.

We have joy in the Lord because we trust in His protection for our lives. We don’t worry or fear; we set ourselves aside to pray and praise the Lord. We celebrate God and all that He is doing for our lives. The joy of the Lord is our strength and stronghold because we have faith in God and His promises.