This thesis examines the representation of transcendent beings in the Jewish literature of the Second Temple period, with special attention to 1 Enoch and the Book of Jubilees. Its aim is to explore how ideas about angels, fallen beings, demons, and heavenly mediators developed in connection with the historical, religious, and cultural changes of the period. Using religio-historical, text-critical, and comparative methods, the study analyzes Babylonian, Persian, and Hellenistic influences, as well as the figures of the Watchers, Asael, and Mastema. It concludes that these traditions do not indicate a weakening of monotheism, but rather form part of theological reflection on the origin of evil, divine justice, and human responsibility. The texts under discussion played a significant role in shaping later Jewish and Christian demonological and angelological thought.