…the function of the priests is to prevent the first, highest, level of cosmic eating, the eating of human mortals by gods. How? By way of performing sacrificial rituals. Gods must be appeased, their hunger for blood must be satisfied, and the trick of the priests is to offer the gods a substitute (symbolic) sacrifice: an animal or other prescribed food instead of human life. The sacrifice is needed not to secure any special favors from the gods, but to make sure that the wheel of life goes on turning. Priests perform a function which concerns the balance of the entire universe: if the gods remain hungry, the whole cycle of cosmic life is disturbed.
Slavoy Zizek, Living in the End Times