The Jewish idea of an afterlife historically comes from a sort of murky, indistinct interpolation of Zoroastrian ideas. It’s not a fire & brimstone deal; Sheol is a sort of dead people and animal place without a lot happening. When the messiah comes, the righteous get to sit at the right hand of G-d, but it’s not so clear why that matters other than being righteous; it’s not like you’re going to party down with the deity in heaven. That said, “Two Jews, three opinions”–many contemporary Jews believe in some heavenish afterlife.
Not surprisingly, Judaism stresses acts/deeds more than belief when defining who is a good Jew/person. Also, if you’re pretty sure this is the only life you get, appeals to reincarnation or a yummy afterlife where you’ll get your reward aren’t as compelling.
If there is an afterlife, is being Jewish is worse than not being Jewish, because you have more responsibilities in order to get in? It seems like you would be better, Pascal’s wager-wise, being an atheist than a Jew, if the actual God is the Jewish one.
Second, are you allowed to leave the religion and no longer follow those extra rules and responsibilities? If I were an observant Jew and really wanted to eat cheeseburgers, and I didn’t want to commit murder, could I renounce my faith and be relieved of those extra rules?
Maybe someone else has an answer to these questions, but my immediate reaction was, “If you’re of a Chosen people, the question of greater responsibility is a given and perhaps a plus.” As to the second, “Nu, so eat the cheeseburger already and stop kvetching.” I imagine this has to do with differences in Jewish and Christian “guilt,” “sin,” and “following the religion.” But there are many gradations of Judaism and they’ll get you different answers.
ETA: I don’t really know how to express it, but these questions just feel so non-Jewish!