Final answer:
The political device's purpose is to illustrate both imperial rule and the belief in divine authority, legitimizing the emperor's power and promoting political stability through an intertwined system of religion and governance.
Step-by-step explanation:
The purpose of the political device mentioned in the statement is both to show imperial rule and to demonstrate the belief and rule of the gods. The imperial cult played a significant role in the structure and legitimization of the Roman Empire, intertwining the emperor's authority with religious belief. This blending of temporal and divine rule was utilized to legitimize the emperor's power and to promote the political stability of the empire. Moreover, in various empires throughout history, public rituals and ceremonies, such as human sacrifices, were used for religious reasons, but served equally as political tools to display power and control over subjects and enemies.