"creator of the universe must have a human sacrifice before he can forgive sin"

Sorry, NO they DONT ! There is the one story of Abraham being commanded to sacrifice his son, but it turned out to the a trick. The crucifixion was also a special case.

They always sacrificed animals ( hence the term Scape GOAT), which is not too surprising, since it was about the only thing that people had of value.

It stems back to religions far older than Christianity and that people are just animals with higher intelligence. People have been brutal for milenia and when you see a volcano erupt or have been in a drought for a life threatening amount of time, people tend to panic first and think later. An animal or human sacrifice was meant to appease the gods to avoid anihilation.
If you look at religions that predate the judeo-Christian religions, you start to see how often they have borrowed from many polytheistic religions.

Indeed

Yes it is very barbaric and makes no sense. Just like why would the creator of the Universe need money? But it is also a part of the elite societies throughout history and many would claim still existing today. This is so obviously a man made concept like the doctrine of Hell where a loving God throws those who don't accept his blood sacrifice into eternal damnation. It is all about guilt and fear and control of the masses. That it is now the 21st Century doesn't seem to have led us into any age of Enlightenment. We are still still stuck in the middle ages as far as our organized religions go.

Some asshole with a blood fetish decided to rule the area, at the time. nobody wanted to argue?