How much more immoral we would be if we didn't have to die! Two thoughts.
1. Death sobers us and conduces to reflection on how we are living and how we ought to live. We fear the judgment that may come, and not primarily that of history or that of our circle of acquaintances. We sense that life is a serious 'business' and that all the seriousness would be drained from it were there no Last Judgment. Some of us, like Wittgenstein, strive to make amends and put things to right before it is too late. (Do not scruple over his scrupulosity but take the message of his example.) We apply ourselves to the task of finally becoming morally 'decent' (anstaendig). The end approaches swiftly, and it will make a difference in the end how we comport ourselves here and now. One feels this to be especially so when the here and now becomes the hora mortis.
DRURY: I had been reading Origen before. Origen taught that at the end of time here would be a final restitution of all things. That even Satan and the fallen angels would be restored to their former glory. This was a conception that appealed to me -- but it was at once condemned as heretical.
WITTGENSTEIN: Of course it was rejected. It would make nonsense of everything else. If what we do now is to make no difference in the end, then all the seriousness of life is done away with. Your religious ideas have always seemed to me more Greek than biblical. Whereas my thoughts are one hundred per cent Hebraic.
(Recollections of Wittgenstein, ed. Rhees, Oxford 1984, p. 161.)
Death has been recognized from the beginning as the muse of philosophy. I supplement, or perhaps merely unpack, the Platonic thought by writing that death is the muse of morality.
2. Lives without limit here below would afford more time for more crime. Death spells a welcome end to homo homini lupus, at least in individual cases.