The episode of the golden calf was one of the gravest sins committed by Am Yisrael. This is the only sin where God promises Moshe that the punishment will be felt for all generations. As a result of this sin the Tablets of the Covenant are shattered, and they are lost – in that original format – forever. However, this sin carries with it another serious ramification- a rupture between Am Yisrael and God, and their transition from “God’s nation” to “Moshe’s nation”. 

Courtesy of the Virtual Beit Midrash, Yeshivat Har Etzion