Why does God need a blood sacrifice?
It goes back to Adam and Eve the first beings they sinned so they had to die some day, because the price for sin is death so they used to kill animals (usually lambs) so that God would get rid of their sins, and they could go to Heaven. But Jesus died for us then rose from the dead (so He is living) so we don’t have to kill animals we just have to pray to Him that He will wipe away your sin and you have to believe that He died then rose from the dead. And if you believe that then you will go to Heaven for eternity.
I don’t think God needs a blood sacrifice at all. Now or ever. It was people who mistakenly believed that God wanted or needed blood sacrifices. The native American indians also believe blood sacrifices are necessart so they offer flesh offerings, and do sundances. God is so far beyond us; that many people put God into things they can understand. The American Indians do it because from their point of view; their body is all they have to give the Great Creator.