One of the most important documents that Orientalists use to doubt the authenticity of the Quran and the prophethood of the Prophet Muhammad (PBUH), as well as to claim that the Quran has borrowed from the two Testaments, is the similarity in the content of the stories of the prophets in the Quran with those in the Testaments. This research employs an analytical-comparative method and draws on both intra-religious (including the Quran, interpretations, dictionaries, etc.) and extra-religious references (the two Testaments, opinions of Orientalists, and historical data) to analyze and evaluate the perspectives of Orientalists around three main axes: the "origins and sources of the stories," the "way the Prophet (PBUH) accessed these sources," and the "changes to the stories during transmission." According to the findings of the study, the predominance of a historical approach to religions and the lack of attention to the unity of the divine source of monotheistic religions, as well as the Orientalists' perspective on the concept of revelation, which they perceive as a personal experience, are the most significant factors influencing the claim that the stories in the Quran were adapted from the Testaments. The results of the research indicate that the familiarity of Orientalists with the Arabic language is accompanied by deficiencies that have affected their investigations; their information is derived from Arabic sources that are sometimes partial and incomplete. Additionally, the animosity and hostile motivations of the researchers have also played a role in this regard.