Why does the Torah command animal sacrifice?
Many people do not like the idea of animal sacrifice. To modern sensibilities, it appears alien at best and barbaric at worst. Why would anyone want to slaughter a goat and sprinkle its blood on an altar?
Rambam appears to accept the premise that animal sacrifice is an undesirable ritual. The Torah commands it, in his view, in order to accommodate the ancient Israel: after leaving pagan Egypt, the Israelites were so enthralled by idolatrous animal sacrifice that it would be impossible to rid them of the practice. Rambam compares the fixation with animal sacrifice to prayer. It would be inconceivable to prohibit prayer, which was, and is, regarded as an essential type of worship. It would have been equally inconceivable to prohibit animal sacrifice. God, therefore, appropriate animal sacrifices for His own services, rather than issue a command that will not be followed. (Moreh Nevuchim, 3:46).
Ramban raises two objections to this view. First, many pesukim suggest that God desires korbanos for their own sake. “The priest shall burn the whole on the altar, for a burnt offering, an offering made by fire, of a pleasant aroma to Hashem.” (Vayikra, 1:9). In Rambam's view, korbanos serve an instrumental purpose: they wean B’nai Yisrael off of a bad habit. This is incompatible with the description of korbanos as “a pleasant aroma to Hashem.” If Rambam was correct, the Torah would not describe korbanos as intrinsically positive.
Ramban’s second objection: many individuals in Chumash brought korbanos when idolatry was not practiced. For example, after Noach was saved from the flood — when the only people on earth were himself and his family — he brought a korban which Hashem found to be a “pleasant aroma.” (Bereishis, 8:21). If the only purpose of korbanos was to accommodate the pagan tendencies of ancient Israel, why would Noach bring one? Why would God approve?
Korbanos, in Ramban’s view, serve an entirely different purpose. Korbanos atone by forcing man to confront his own mortality. (Ramban, Vayikra 1:9). The sacrificial process is intimate and gruesome: the sinner places his hands upon the animal, says viduy, and then watches it be slaughtered and burned. A moment ago, this was a living creature; now, it is a carcass. Animal sacrifice is a ritualistic meditation on our closeness to death. Because life is so delicate and so fragile, it cannot easily tolerate sin. We are not resilient enough to bear error: we are too mortal for that. Were it not for God’s kindness, life would not tolerate sin at all. But God, in His Mercy, allows his small creatures to recognize their smallness as recompense for their mistakes.