Upon reading the afterword to Letter to a Christian Nation
I got to thinking about blood sacrifice. It's not necessary for you to read this link, and I'm not even necessarily wanting a discussion about the link; I'm just giving context.
Here's where my head is right now, though. In the days when Judaism and Christianity were having their major cultural foundations laid, the people depicted in the Scriptures in question were certainly a product of their times. Those people had certain expectations about how exchanges with supernatural beings worked. There was an unquestioned assumption about the rightful place of blood sacrifice that we really don't tend to have today. The assumption was that blood was a (literal or symbolic) manifestation of life itself, and that giving this to a divine figure would please it.
From this widespread assumption seems to spring everything from Abel's sheep to Abraham's son to Jesus himself. Without the assumption that blood sacrifice and offerings of live creatures is pleasing to a deity, the whole system falls apart. It seems to me that part of the reason why the "Jesus Christ died for your sins" narrative falls flat for a lot of people is that a lot of people just don't understand anymore why there was anything about that in "the rules" to begin with. They don't even understand why YHWH wants
blood, let alone how big a deal it was that his own son was offered up. The "why" of it is lost because we aren't supposed to give blood to our gods anymore.
Aside: if you think blood sacrifice is still considered part of polite religious worship, consider how afraid people are of Santeria for doing what Jewish and Christian scriptures clearly state gods want us to do.
For me personally, this means that while the "God spilled the blood of his only-begotten son to pay the blood debt humanity owed for their sins" narrative had broad resonance at the time
(because basically every culture shared the assumption that a sin was a debt owed to the gods which could be repaid in blood), it has no meaning or place in societies where blood sacrifice is considered something that "savages" (word used with full scare quotes because I'm an anthropologist and can't say "savages" unironically anymore) do. If Christianity is dying, it is because the most central assumption that makes the whole thing work just doesn't have any relevance anymore.
Now, I'm anticipating somebody with a Christian background saying, "Well, the crucifixion was such a badass sacrifice that it ended the time of blood sacrifice, and nobody ever need repay YHWH in blood again." I think this is dodging the issue. The issue is that your potential converts probably don't understand why there ever needed to be a sacrifice in the first place, because they weren't raised to believe that blood sacrifice is Just What People Do. These people need to be convinced first that blood sacrifice is a natural and desirable thing, and I don't think Christians can make that case. Please feel free to prove me wrong if I'm underestimating you.
If the rule is that divine powers can be propitiated with blood, whose rule is that? Did YHWH make that rule, or is it a rule totally external to YHWH by which YHWH is bound? Seems most likely to me that it's the latter. It's a rule external to YHWH by which YHWH is bound because that's how humans thought they had to be interacting with gods. YHWH is a god. Therefore we have to interact with it by giving it blood. If we really seriously screw up big time or just really want to say "I love you" in a big way, we have to give YHWH particularly awesome
For ancient people this was a serious "well duh" sort of a thing, but lots of people don't think
like this anymore. Even the idea that someone else can rightly pay for the sins of another
is considered unjust and barbaric by lots and lots of people. For Christianity to remain relevant, then the practice of valuing blood sacrifice has to be explained, justified, and thereby preserved for your religion to even be intelligible
to modern people. Can you?