The Jews also did not believe in the resurrection of souls either and based their hopes of immortality in their ability to create offspring. Just because they believed something doesn't make it so.
They believed that their messiah would be earthly not spiritual, and certainly Jesus did not teach according to that idea.
As for Gehenna, it is an actual valley and was for future punishment. If it was meant as a purgatory then the Jewish idea was limited to one year. Again, that this was their conception of an afterlife does not make it any more real than an other idea they may have had that was their imagination. A belief in ghosts by the Irish doesn't make them real.
"The Jews also did not believe in the resurrection of souls either"
Of course they did.
See 2 Maccabbees, written about 150 years before Christ.
The Sadduccees didn't believe in the resurrection of souls.
The Pharisees did.