Well of course we believed in reincarnation. It makes it a lot easier to be
sacrificed or to do the deed if you know you're coming back. When death is
no more than a temporary inconvenience, regardless of the sense of loss at
the time, you're going to have a different mindset than if you believe here
and now is all you've got.
This may have something to do with the need to personify good and evil as
did so many Middle Eastern religions, in which the formula was either "when
you're dead you're dead" or "you only survive if some judgemental God has
decided you're worthy", whereas in a religion in which the cycle of birth,
death and rebirth was continuous the whole thing worked itself out without a
need to personify such things. There's always a next time, and all your
debts will be repaid.