זוהר בראשית — דף רמא ע”ב

Israel left Egypt with faith, for it was faith that brought them out. Whoever did not believe did not leave. The secret is that faith is the key to redemption. Every exile of Israel depends on the power of its faith for redemption. Faith in the Holy One, blessed be He, is what protects Israel in every generation. It is the faith transmitted from generation to generation that sustains the people of Israel.