Two somewhat contradictory statements on the same building.
I'm pretty certain Christian theologicians have some clever answer to it, but it seems to me that death being defined as the *permanent* cessation of life is *logically* incompatible with returning from the state of being dead. So either Christ did not die by this definition, or he did something logically impossible. In which case a square circle could just as well have taken away our sins. Simply deanimating and reanimating - while definitely impressive - doesn't quite cut it when compared to being truly dead (since any decade now we are likely going to see cryonics patients repeat the trick, and we already have small animal and tissue models that do it).
Another interesting thing is of course the immortalist position stated here. Many bioconservative arguments against life extension ought to apply to heaven too. Stating that the particular properties of heaven preclude i.e. lack of meaning and achievement implies that such problems might be solvable in the living world too, turning it into a completely empirical question.