Jews believe in life after death. We call it the World to Come.
Is this like the “Heaven and Hell” of other religions? Not really.
We are taught that a person who is completely righteous immediately receives an eternal afterlife. A person who was not completely righteous, however, may still merit this eternal afterlife. The only way he fails to merit the afterlife is if he intentionally acted in a way that completely severed a connection with the Creator, without repenting for his deed that caused the severance.
We are taught that a person who was not completely righteous will undergo a certain purification process that is also part of the World to Come. This process, known as gehinom, is an opportunity for his soul to get a chance to "think objectively" about his lifetime spent on earth. Depending on how the person spent his life, this can be a painful process in which the soul mourns its bad deeds, lost opportunities and wasted potential. The maximum time limit of this process is twelve months.
Ultimately, the gehinom process is temporary, and eventually enables the person to enjoy the benefits of all the good things he did during his lifetime.
Nevertheless, Judaism emphasizes life in this world. Here's a parable to explain: A wealthy man goes on a cruise ship. The ship sinks, and he finds himself afloat in a tiny rubber raft. This raft is his only hope of arriving safely to his family, his mansion and all his wealth. Judaism looks at this world like a raft. By following the survival manual - the Torah - this little raft can bring us safely to the World to Come.
