That last part is so true!!
But Jesus led a sinless life(unless you believe the Infancy Gospels to be canon
), so I'm afraid it still makes no sense. But good for trying to explain it. ^_^
Though I think I might get it; you mean a spiritual rebirth... happens to me all the time. (I'm quite serious when I say that... every time I grow in my spiritual wisdom, I "die" and am "reborn" again) To me, the "punishment" is the humiliation from learning that you were wrong. (NOT a pleasant feeling, to say the least) and the "rebirth" is the realization of what you now know. ... that what you're talking about? Or maybe death as a sort of "withdrawal symptom" of stopping an addiction, which regardless of what the addiction is, is EXTREMELY painful. But once that's over, freedom is achieved.
I'm afraid that with those two explenations, that makes the Wisdom of Jesus far more important than the death on the cross... I don't at all agree with the idea Paul gave that "faith in Christ is useless unless he died and was resurrected". ... then again, I don't agree with most of what Paul said...