God ruled that there is no remission of sin without shedding of blood. This was because, the life of the flesh is in the blood.

God also demonstrated how He would fulfil His promise of a Saviour, as per His original plan, by slaying a lamb to provide clothing for the first couple to cover their shame. The shedding of innocent blood showed man that sin would bring forth agonizing death. He also instructed man to offer an innocent animal as a substitute to remind him of his punishment. This would continue until the actual substitute Jesus would come to shed His own blood for the remission of sin of mankind.

A substitutionary death of this sinless Man for the sin of the world was due in its time and came in His-story approximately 2000 years ago. Since then, no such animal sacrifice has been necessary.