Korbonos Sacrifices

Nefesh Hachaim, (by Chaim Volozhn, the student of the Vilna Gaon) explains,
that the reason for the korbanot (sacrifices); the sacrifices serve as the food of the world:

Just like when a person doesn’t eat, his or her soul begins to leave, and he or she feels faint; so too, when the world does not have the Beit Hamikdash, where the sacrifices (food) can be brought, the world becomes faint.

The world becomes faint, because there is no karbanot to keep the world’s soul (Hashem) in it.

This is one of the reasons, why the world today, is really detached from spirituality, and anything beyond the physical; as opposed to how it was in past.