Verse 55 of Surah An-Nur is one of the key verses of the Holy Qur’an regarding God’s divine promise to the believers for succession and the establishment of authority on earth. This study, through an analytical and comparative approach, examines the exegetical perspectives of both Shia and Sunni scholars concerning the fulfillment of this promise. The findings indicate that Sunni commentators such as al-Tabari, Ibn Kathir, and al-Qurtubi interpret the realization of this promise as having occurred during the early Islamic period—specifically, in the time of the Prophet Muhammad (peace be upon him) and the Rightly Guided Caliphs. In contrast, Shia exegetes, including Allameh Tabataba’i and Ayatollah Makarem Shirazi, believe that the complete and final fulfillment of this verse will take place in the future, during the reappearance of Imam al-Mahdi (may God hasten his reappearance). In both perspectives, the conditions for the realization of this divine promise are faith, righteous deeds, and pure monotheism. The results of the study reveal that although both schools of thought affirm the principle of divine succession (istikhlaaf), they differ significantly regarding its ultimate manifestation and scope of realization. These differences stem from the theological and narrative foundations of each tradition. Moreover, the divine promise of succession is not only a prophecy of future triumph but also a civilizational strategy encompassing moral, identity-based, political, cultural, and psychological dimensions—serving to strengthen discourse, reengineer social structures, and guide the educational direction of the Islamic system in the contemporary era.