Between sacrifice (gifts to God as thanks the bountiful harvest and to ensure subsequent success) and literal scapegoating for perceived wrongdoing, more extreme and symbolic forms came about (e.g., the "perfect blood sacrifice" of Jesus to wash away the stain of human sin). It doesn't make sense when you really think about it, but theology has been built upon it in ways that make it foundational to some religions like Christianity.

Research from a couple of years ago suggests that, in the first instance, human sacrifice was related to social stratification.

[nature.com]

Makes a lot of sense but not so sure about the method of the research.

The truth? In my opinion, it is altruistic symbolism that goes with a theme. When you decide to follow a religion/tribe; you are choosing to sacrifice your body, your individual judgment, your free will, indeed your rational mind, to the authority of the leadership of the tribe. You are no longer an individual, you have sacrificed that part of yourself to the authority of another that claims to speak for/commune with the authority/majority of the tribe. The proxy sacrifice that you witness the authority perform, reminds you that no individual is above having that wager called upon, to bring about prosperity for the rest of the group on your behalf. But don't worry, they forever promise to remember your sacrifice... until the next hardship befalls the tribe.

No shit, Sherlock!

Sacrifice virgins to keep the reproductivity high in the group. Sacrifices of food feed the priests. Sacrifice the son of god, well just couldn't let him keep saying things like that.

I don't know about all cultures, but the judeo Christian bit has in its usual historic game of telephone, changed over time. The Jews liked to sacrifice a ram because it pissed the Egyptians off . The ram was the symbol of one of their gods. It's kind of like a high school pep rally where they burn the opposing teams mascot in effigy to rally the troops against the opposition . The Christian myth makers just ran with this one and changed it to lamb.
Other cultures have their own varying excuses for barbaric behaviour .

I wonder if the sacrifice was to help normalize the graft required by the powers that be or the tribal bully. Payment of bribes must be OK because god demands it also. The priesthood usually did pretty well on what the god left behind. I don’t have evidence, just a question.

Back then those things were of great value, and your "jealous gawd" demanded such. Still does......

About the only validity I’ve found for the Chirster’s displacement of various ‘indeginious religions’ was their having stopped such ‘sacrifices.’ And have never understood the reasoning for such killing & murder … yet each guilty religion will/ would describe some value to it..

Just struck me (after reading someone bad mouthing Atheism over Agnosticism; if an Atheist said, ‘killing animals & humans to appease your god is wrong,’ would an Agnostics view be, ‘I suppose you may continue this killing’ … ‘as I’m not sure there isn’t something useful happening because of it’

In my opinion...it's the root problem and the sickness of humanity...ASSUMPTIONS. Instead of living off a basis of what we can know and test...we make assumptions that God wants this/that/the other. We assume he/she is angry...wants something...etc. After several years of sacrifice failure to fix all of people's problems, you would think we would all wise up and see the big picture?!? Then again...people are still giving boat loads of money, estates, and such to swindlers like TV preachers so maybe humans are doomed to believe just about anything without proof or confirmation?