I feel the same, Alasdair... about Jesus's sacrifice not really being sacrifice. It never made sense to me (If in-fact I'm getting Christianity and the idea of a heaven-place after death where we go to reside).
I would in-fact trade my pain and suffering that I've experienced here for his experience. At least his was quick (relatively), where my predicament insures I'll live for some time, just deficient in quite a few things, a lot of the time, or suffering allergic reactions from the air I'm breathing. Yea.. I'd much rather be beaten and cut up and bones cracked and made fun of for an entire day, and then go to heaven, then come back renewed. Not sure if it's not all just symbolic though.
Anyway not the point I guess.
To answer the OP, I believe that full circle, I am everyone else, and they are me, so according to this, what you propose simply won't work. But... assuming somehow I'm wrong, no... I wouldn't sacrifice my life and soul for "everyone else". Not a fucking chance. I would however die for people.. if it simply meant me actually trading my literal life (not some other way of looking at my life, like God has done. meaning he's taken/taking my life away while leaving me alive to see it.) here... and "blacking out"... I don't think that that would be a bad deal... to ensure that at least someone, everyone else, gets to experience ecstasy and enlightenment. But I wouldn't endure everlasting torture, by choice. There'd have to be a stopping point for me to agree.
I think sometimes when religion speaks of "eternity", and big numbers like "I saw seven thousand"... I think they're being children. There's some seriousness to it, but there's some... not so serious. There's no way (? that i see that) anything that finds a reason to talk at all like this could see seven thousand of something and know that it's exactly seven thousand of something. Bible uses lots of big numbers like this. Eternity could mean a thousand years. Could mean a million...
My cut off is an actual number. If it's an actual number, I most likely would.. but an eternity... eeeeeeeeehhhhhhh.
I have a problem with the idea that this scenario would ever exist, though.
But in a way I guess I see how it could.
I'm bouncing around.
Sometimes I do feel that's the only way it does exist.
Maybe Jesus is really always on the cross, in torture, in some sense.
I guess if I knew for sure that what I'm enduring, If I knew at all times that it was providing light for people (like, I'm on fire and lighting the world, but of course, I'm in pain.)... if I knew, I would. Yea... But only if I knew for sure that I was a bad-ass on fire... if I was just in pain and confused/my awareness demented, I don't think I would be too happy with it. If I knew... possibly.. Jesus.. but an eternity? WTF is that? I simply don't feel it exists (I mean it does.. but...). At least not in any form applicable here. AHHHHHHHH.
(hard question)
I'd rather take turns being on fire.