Reply #7: Well the whole surviving in the afterlife thing was a later introduction

[dmallind]

Not later than Ecclesiastes, but later in the sense of only being included in those texts written in the postexilic period.

The fact that Zoroastrianism contains belief in an afterlife is of course purely a coincidence ;)

IIRC Ecclesiastes is written a couple hundred years after the exile. Maybe a bit more. So at least some sects had it as a belief concept by then.