Let me deal with some of your comments.
Garyvdh makes two interesting points:
(i) according to some, Jesus did not die for everyone, just the chosen ones. (I hope these people will avoid promoting their religion by saying to all and sundry, “Jesus died for your sins!”, then, for, according to them, he didn’t.)
(ii) atheists cannot do what Jesus/God did.
These points are both true (and I was, in fact aware of them). But they are irrelevant, aren’t they?
My point is, atheist have willingly made at least as admirable sacrifices (if not an identical sacrifice). And many would be willing to make such a sacrifice if they could. That they cannot do precisely what Jesus did is irrelevant, surely.
"Perhaps a better analogy would be this: Would your hypothetical atheist be prepared to die an excruciating and humiliating death at the hands of his enemies, in order to save the very people who were killing him? Who are the most offensive people imaginable? Would you die to save them, regardless of whether you believed in a resurrection or not?"
Well, Garyvdh has just provided me with a response to this point: Jesus did NOT die for everyone, so he may well not have died for those who killed him!
But (putting that Calvinist stuff to one side), actually, an atheist might allow himself to be killed by his own morally depraved family, if, he loved them deeply, and if he was convinced that, by doing so, he could save them (both their lives and their moral characters).
Actually, I suspect I’d do this for my family (er, not that they're morally depraved - but if they were...). And I’d do it knowing I wouldn’t be resurrected. See? – that’s a more admirable sacrifice than Jesus’.
I nearly included Sam’s “Jesus didn’t fully know what was going on” response in my original post. Actually, Jesus clearly knows his death is not the end of him. He is explicit that he’s going to the Kingdom of God, will sit with God, etc., see e.g. Mark 14.25.
But in any case, even if he didn’t know his death would not be the end of him, Jesus’ ignorance of the fact that his death would not be final only then brings his sacrifice up on a level with sacrifices made by atheists (in terms of admirableness). His sacrifice still isn’t more admirable than theirs.
[P.S. Incidentally, bear in mind I am focussing on what is the most admirable sacrifice, not which is the “greater”, as on some conceptions of “greater”, Jesus’ sacrifice can’t help but be the greatest as he sacrifices God (i.e. himself).]
[P.P.S. Further point to anonymous - in any case your analogy isn't right as of course Jesus died to save all of us (or at least Garyvdh's "chosen ones"), not just the handful of individuals who killed him. Yes, I might allow myself to be killed by nasty evil Bert, if, by so doing, I can save the life of not just Bert, but a million others.)