Since the law has only a shadow of the good things to come, and not the reality itself of those things, it can never perfect the worshipers by the same sacrifices they continually offer year after year. Otherwise, wouldn’t they have stopped being offered, since the worshipers, purified once and for all, would no longer have any consciousness of sins? But in the sacrifices there is a reminder of sins year after year. For it is impossible for the blood of bulls and goats to take away sins.

Therefore, as he was coming into the world, he said:

You did not desire sacrifice and offering,
but you prepared a body for me.
You did not delight
in whole burnt offerings and sin offerings.
Then I said, “See—
it is written about me
in the scroll—
I have come to do your will, God.”
(Hebrews 10:1-7)

According to the law almost everything is purified with blood, and without the shedding of blood there is no forgiveness. (Hebrews 9:22)