Dave you have not proved your claims, in fact I am not sure if you have even defined them. You have not shown for example, who influenced who, what relationships did they have to each other?
From the Catholic position, they in the past have shown that Jesus taught the disciples, who in turn taught some of the church fathers — a chain of evidence.
It is this chain of evidence that is missing from your claims.
Just because two people believes the same thing, does not prove they conspired with each other.
From my perspective, it’s the “chain of evidence” that’s lacking in popular Christian conception. To me, there are two significant disconnects: the first being between the conception of the afterlife in pre-333 BC Israelite religion and the New Testament, and the second being between the New Testament and the popular understanding of the soul and afterlife.
It’s difficult to explain Platonism concisely, but basically Platonists see two worlds: the material world and the world of invisible ideal forms. The material world is changeable, corrupt and deteriorating, but the world of ideal forms is perfect and eternal. The soul is that which belongs to the world of ideal forms and through which one can transcend the material body and with it, the material world. At the end of life, one’s soul returns to God.
The way “soul” is understood in the New Testament (say in 1Peter or Revelation) to me is drastically different from
nephesh in the Old. So one naturally asks, why the shift in understanding? Given the strong influence that Greek culture had on early Judaism (again see Philo), this seems to be the most likely candidate.
The popular Christian understanding of the soul is that the human being is conceived, becomes invisibly “ensouled” at some point, that the soul is eternal, that at the point of death one’s soul goes to heaven or hell (or I guess purgatory), and that one day the soul will be reunited with a resurrected body. Dualistic divisions between body and soul are strictly maintained.
To me the New Testament doesn’t spell out these ideas very specifically at all, at least not specifically enough to derive concrete doctrines about them. So again, naturally one asks where the ideas come from, and it seems that the most likely candidate would be Greek philosophy, since a significant chunk of the early Church operated within Greek culture and the ideas are relatively similar.
One could pose a similar type of question about the notions of demons or Satan for that matter–virtually absent from the OT, but appear everywhere in the New.