The book of Hebrews explains how Jesus put sin away by the sacrifice of Himself. He accomplished something the blood of animals could never do in the first covenant and even before that—sins were taken away, once for all. Let’s think this through. When did this happen? And prior to the cross, how many sins had you committed? Did Jesus only remove the sins of the world up to the moment He died? If so, Hebrews 9 explains that this would mean He would have needed to suffer often since the foundation of the world. Jesus isn’t shedding any more blood, and this is great news for us.
Under the Old Covenant, there were many priests who would serve under the law for many years or until they died; other priests would then replace them. They offered many sacrifices for the sins of the people, as well as their own sins. But the New Covenant would usher in a different priesthood with Jesus Christ, who was perfect, holy and undefiled. He would become the one and only mediator between us and God through one sacrifice for all. When did this occur? It came after the law, when the Old Covenant would be put aside and forgiveness would last forever. The shedding of blood is no longer needed.