There is an afterlife, whether some people in Judaism chose to deny it is pointless since your opinion on a fact doesn't change the fact. In any event Jesus
For when they shall rise from the dead, they neither marry, nor are given in marriage; but are as the angels which are in heaven. 26And as touching the dead, that they rise: have you not read in the book of Moses, how in the bush God spoke to him, saying, I am the God of Abraham, and the God of Isaac, and the God of Jacob? 27He is not the God of the dead, but the God of the living: you therefore do greatly err.
(Mark 12:25-27)
It's just shows that the debate was in that period, Jesus showed that they were in error and that there was an afterlife.