Parashat Vaera
Years ago I got one of those telephone calls I dreaded. "Rabbi, my name is so and so, and I am a student at the Nazarene Seminary (their international seminary is in Kansas City). Rabbi, I am looking for the appearance of afterlife in the Torah. Rabbi, there's no afterlife in the Torah, is there?"
I was so relieved that I did not have to tell this student the truth, that he had arrived at the truth on his own. I hate the feeling of undermining a person's theology, but also feel the necessity of stating the truth.
Afterlife as we think of it, olam habah, "the world to come" of rabbinic theology, originated in the Greek world in the second century b.c.e.  It's an historical anachronism to claim its appearance in Torah. All Jewish movements for the last 2,000 years have affirmed an afterlife, but not necessarily its foundation in the Torah.
The Rabbis (Hazal) take great pains not only to assert the belief in afterlife, but to claim that anyone who does not believe that afterlife appears in the Torah will not inherit it. The classic proofs are found in the Babylonian Talmud, Sanhedrin 90b (Soncino Talmud, Nezikin, Vol. III, p. 603ff).
One of the citations appears in this week's Torah portion, Vaera, from Exodus 6:4. Stating that God appeared to the patriarchs, the Torah continues, "I also established my covenant with them, to give them the land of Canaan..." As the Soncino commentary and Torah Temima both explain, the only way God could give Abraham the land of Israel would be if he were to be resurrected!  Thus, afterlife appears in the Torah: QED.
But why must Hazal go to such lengths to prove the Torah origin of afterlife, even threatening non-believers with exclusion? Why is this doctrine so important?
Resolving the problem of human mortality is the classic foundational problem for religion to resolve. (Have you seen Woody Allen's movies, including the most recent, Magic in the Moonlight?) Western religions resolve the problem with the doctrine of afterlife: viz: we don't really die!  We actually transform to a different state: a bodyless state where we are all soul and no body, in another realm.
Since I am such a staunch believer in afterlife, you should not think I am mocking the belief. I am not. Like the classic rabbis, I believe in afterlife and think reincarnation is likely.
But we live in a world in which spiritual matters are not subject to definitive proof. We rely mostly on our personal experience in deciding this most essential question: does life continue after death?

The only part of this question that I find confusing is that we do not discuss it more in polite conversation. It seems to be the subject of quiet and private conversations, like cancer and sex once were: not something to be discussed in polite company. But, as the Rabbis and all religious authorities understand, the reason and meaning of our existence are the raison d'etre of religion, and basic human concern. More, not less, light should be shown on the subject. More public and personal discussion should be held, so that we understand our own position, and come to grips with the universal and age old human question: what is the meaning of my life?