Here is a deeper explanation of the role “blood” has in redemption and, also, a key verse. The people were not to handle the lives of animals carelessly or irreverently because the blood is that which takes the place of the sinner on the altar and rescues him from death: “For the life of the flesh is in the blood, and I have given it for you on the altar to make atonement for your souls, for it is the blood that makes atonement by the life” (17:11). This blood of the sacrifice is so sacred and precious that, wherever the animal was sacrificed, the blood must be brought to the tabernacle and offered as a gift to the Lord. This, rather than giving the blood to the idols, the goat demons (17:7).
More, here, about holiness and the priests and how Israel was to live but, always, the blood was front and foremost. For Israel there was one place of atonement, one tabernacle, one place they could meet with God and have their sins dealt with. Their own efforts could not save them. The idols had no power to save them. Human religion and philosophy were worthless. But the blood! The blood offered to God at the tabernacle! The blood of the Savior! This is why we sing:
What can wash away my sin?
Nothing but the blood of Jesus;
What can make me whole again?
Nothing but the blood of Jesus.
Oh! precious is the flow
That makes me white as snow;
No other fount I know,
Nothing but the blood of Jesus.
&
Just as I am, without one plea,
But that Thy blood was shed for me,
And that Thou bid’st me come to Thee,
O Lamb of God, I come! I come!