That's who Jesus Christ is. He became the final Priest and the final Sacrifice. Sinless, he did not offer sacrifices for himself. Immortal, he never has to be replaced. Human, he could bear human sins. Therefore he did not offer sacrifices for himself; he offered himself as the final sacrifice. There will never be the need for another. There is one mediator between us and God. One priest. We need no other. Oh, how happy are those who draw near to God through Christ alone.