Is it "wishful thinking" to believe in continued existence after biological death?

It is more accurate to talk of “continued existence” after biological death, rather than an “after life” – because, while all pre-modern societies agreed that death was not the end; there was a very wide range of fates described. 

Even the post-mortal fate of “reincarnation” – which has probably been the majority view through the whole of history, due to its dominance in the East, as well as the earliest known societies – has multiple, and incompatible, sub-types. 

I find it very striking, and important, that most ancient and historical societies that believed in continued existence after death, anticipated a more-or-less miserable post-mortal fate – Sheol and Hades for example, or Ragnarok. 

This tells me that “wishful thinking” was certainly Not a major motivation through most of history and in most places; and to suppose it was is just a typical piece of modern self-willed ignorance and "projection": a consequence of our endemic incapacity for coherent thinking. 

And the Good News of resurrection and Heaven after death for those who followed Jesus Christ, was surely the single most powerful reason why Jews and early pagans embraced Christianity. 

If pagans or Jews came to believe that Jesus was divine, and that Jesus’s promises were true, then it was a “no brainer” to become a Christian because it was already assumed that there would be continued existence after death; and Christianity offered a far better continued existence than any other religion.

Note: The above came from a comment I made to a meditation on death by Bonald at the Orthosphere. Bonald responded to my comment thus: 

"Even Christianity and Islam only hold out heaven as a possibility, not a certainty. I can’t think of any religion whose idea of the afterlife matches what anyone would wish for". 

In other words; if religions really did manipulate the masses by offering to fulfil wishful thinking, then they could do a much better job of giving people exactly what they most wanted after death, and making this reward easier, surer, and more straightforward to obtain. 

If wishful thinking really was the basis of after-life claims; then it would be expected that religions would compete in offering better and better lives beyond death, on easier and easier terms. 

But this does not happen - to any significant degree, and not between the major religions.

This is one reason why I tend to believe that - in some overall sense - all religions are broadly accurate in terms of their claims for the after-life; because (within constraints) God gives people "what they ask for" or "what they want" after death. 

(What they want/desire provided subjectively, in his experience, for that person - not necessarily or usually in terms of what he wants for other persons: God does not sacrifice his children to each other. ) 

Damnation is therefore, in its essence, inducing an individual to ask-for and want damnation after his death; and annihilation is what (apparently) many or most modern people ask for and want, following death.