Sacrifices as a subject do not really excite most of us nowadays. The very idea seems rather off putting. But the fact is that we sacrifice vast numbers of animals around the world every single moment. We kill them for food; often under the most cruel, barbaric and unsanitary of conditions. But as is our practice nowadays, we try to hide anything unsavory from the public eye. If people actually saw how animals are slaughtered in America today, regardless of method, most would find it very difficult to eat meat afterwards.
In the Temple killing animals for food was ritualized in an atmosphere of different chambers, taking animals gently through quiet courtyards, with incense disguising the smells and priests in ceremonial clothes creating an atmosphere of peaceful ceremony rather than brutal killing fields. You placed your hands on the animal, establishing a personal relationship rather than the impersonal conveyor belt of modern slaughter.
When we pray for a return of the sacrificial system we pray for a more ceremonial, gentle humane way of life. The fact is that we may never actually reinstate animal sacrifices. Besides the Torah itself offers the option of the Minha, a vegetarian offering. Perhaps all future sacrifices will be vegetarian.
Our tradition tells us that in the future Elijah the prophet will come to teach us how to re- establish ancient rituals. We have no idea what we will be instructed to do. Perhaps he will tell us how wasteful it is to spend so much of our resources in breeding cattle for slaughter rather supporting poor human beings and starving children. Who knows?