The Jewish Church did not have any way to officially promulgate doctrine (and this is still the case today). There is no such thing as an “official” Jewish teaching. Most teachings are a consensus of rabbis but carry no definitive authority.
In Biblical times the Jews were divided on even the question of an afterlife (and any spiritual existence other than God - even angels were disputed). Paul used this difference of opinion to distract the Sanhedrin, who had put him on trial:
Then Paul, knowing that some of them were Sadducees and the others Pharisees, called out in the Sanhedrin, “My brothers, I am a Pharisee, descended from Pharisees. I stand on trial because of the hope of the resurrection of the dead.” When he said this, a dispute broke out between the Pharisees and the Sadducees, and the assembly was divided. (The Sadducees say that there is no resurrection, and that there are neither angels nor spirits, but the Pharisees believe all these things.) [Acts 23:6-8]
This caused a knock-down, drag-out fight and angered the Sadducees so much that they plotted to kill Paul in an ambush of 40 men - the plot was thwarted by the protection of the Roman governor.
Obviously, if you don’t even believe in an afterlife, you won’t believe that prayers affect it.