Why does Adams think the Declaration is worth celebrating, in spite of the cost?

Adams think the Declaration is worth celebrating, in spite of the cost because:

John Adams wished that the fourth of July will be celebrated with a lot of pomp and joy, topped with celebration and fireworks. He believed that this day will be celebrated because he called it as a "day of deliverances by solemn act of devotion to the God almighty".

He called it a divine event which has to be celebrated with the utmost grandeur across the entire continent. The approval of the crown to grant independence to the thirteen colonies is something which has to be celebrated in the upcoming years.