2 Chronicles 30:26-27 So there was great joy in Jerusalem: for since the time of Solomon the son of David king of Israel there was not the like in Jerusalem. Then the priests and the Levites arose and blessed the people; and their voice was heard, and their prayer came up to his holy dwelling place, even unto heaven.
During the great renewal of the Passover Feast in Jerusalem under the reforms of Hezekiah, there was great joy in the city, for nothing had been seen like this for several hundred years. How that could happen no one knows, but we can imagine the powerful joy that filled the days of the worship celebration in the reinstitution of the Passover, something that no one present had seen before.
The Passover looks past to the great deliverance that the Lord brought about in the Exodus event. It also looks forward to the future Deliverance event on the cross when the Messiah, the Lamb of God, would sacrifice Himself for the eternal deliverance for all from sin, death, and the devil forever. This looking backward and forward elicits great joy from the participants.
Even so, the same kind of enthusiastic joy is produced in the NT believer, who, in the Divine Service of Holy Communion looks back to the Cross and the Tomb and forward to the Marriage Supper of the Lamb in the eternal kingdom. Even if the emotions do not always feel the joy, the spirit knows deep in the heart the inexpressible joy.
And nothing and no one can take that away. Awesome joy takes hold of our spirit when we meet God and receive His love. This inner joy is meant to last all week long, no matter what threats and scares come our way.