Why does God require sacrifice and penance in order to forgive us, yet expects us to forgive each other without any additional prerequisites? I don’t think a sufficient reply from Christianity is just to say God is holy and perfect. During the Bronze Age (and earlier), societies embraced sacrificial and purification theology/mythology and now we relatively enlightened modern people, for very humane, moral and intellectually credible reasons, mostly do not. Humanity has largely, at least ideologically, rejected several particular old world ways that have held back and/or diminished human quality of life. These are things such as slavery, misogyny, theocracy, seasonal and colonial warfare, animal sacrifice, and the death penalty for “crimes” such as adultery and being an unruly teenager. All of the abhorrent beliefs and practices just listed were directly or indirectly endorsed in the Bible.
There did seem to be a progression towards higher, more accurate ethics as divine inspiration continued year after year from Genesis to Revelation. Therefore, it seems to me most reasonable to discard these unethical beliefs that represent the old savage and brutal way of life and of viewing God. I’m not saying that all of Christianity should be ignored or thrown away. There is clearly a lot of vitality, wisdom, and illumination in the Scriptures. But it’s a hodgepodge of good and bad information that both hurts and aids the world, and which ought to be sifted through to see what’s still working for the fulfillment of civilization’s (and the rest of nature’s) legitimate needs and those unique desires that truly lead to holistic wellness.
I’m pretty sure that the requirements for sacrifice and penance were made up by men, so the question might be more properly “what is it about human nature or motivations or psychology that would come up with such a requirement?”
It all has to do with this obsession with blood. For some reason, bloodshed is determined to be efficacious in making things right.