Despair, virtue and the afterlife

1. If it is physically guaranteed that virtue will perish, despair is the right attitude.
2. If there is no life after death at least for the virtuous, it is physically guaranteed that virtue will perish.
3. Despair is not the right attitude.
4. So there is life after death at least for the virtuous.

Making this argument precise would take some work. One would want to say something about the scope of "virtue" (human virtue? individual virtue?), and one would want to say a little more about "right attitude".