The concept of offering animals on a mizbeach is a recognition that man is above animal. Man is not meant to worship animals, but to bring them up to a higher level of sanctity. In Mitzrayim the Egyptians serve animals. Shabbos Hagadol was when the Jewish People set aside the lambs for the Korban Pesach, and while the Egyptians would usually have been furious at this blatant disrespect of their gods, they were completely unable to do anything. We have a choice to treat the animals as something to lift up, or to spend our lives pursing animalistic tendencies and worshipping the animal. We can head towards Hashem, or we can head towards emptiness and nothingness.