No Passover like it had been kept in Israel since the days of Samuel the prophet. None of the kings of Israel had kept such a Passover as was kept by Josiah, and the priests and the Levites, and all Judah and Israel who were present, and the inhabitants of Jerusalem.
2 Chronicles 35:18
This was worship that was celebrated like no other kind of moment. It was the defining "return" to God of Josiah's reign. The text says that nothing in Jewish living memory was like this Passover under Josiah. The nation had to read about the days before the monarchy to have known such a large scale, unified commitment to celebrating God's love and deliverance.
The sad reality was that Passover was supposed to be a yearly celebration. And it was meant to be the kind of experience described in this text every time it was celebrated. Although it is exciting to see the zeal for God found in this passage, it is also quite sad to realize the people of God rarely worshiped with such joy in their hearts.
Passover is rooted in the delivering love of God. It was the center of the life of the average Hebrew in biblical times. It was meant to pull the people into a common remembrance and celebration of the deliverance that defined them. God has always wanted His people to celebrate His saving love.