It is not their meat, nor their blood, that reaches God; it is their piety that reaches God (Al Quran 22:37) The aim of sacrifice, like all other Islamic essentials, is piety and self-righteousness. Eid ul adha is a time of sacrifice. Qurbani, like Zakat, is essential for one who has the financial means and savings that remain surplus to his own needs over the year. It is essential for ones own self.