I’m a Reconstructionist Jew. Many Jews, besides Reconstructionists, do not hold a belief in life after death.
If religion is a device created by humans to over their fear of death, then why Judaism? Our rituals and practices gain us no merit with God. We do not believe in Original Sin, and therefore we do not perform mitzvahs or commands of the Law of Moses in order to gain atonement or to be made right with God.
Many Jews do not believe in God. Reconstructionsts, for example, generally do not hold God to be a divine Person that hears or responds to prayers, that punishes the wicked or rewards the good. Yet being that we stem from Orthodox Judaism, you will find that many of us live very Torah-observant lives, pray regularly daily, go to synagogue frequently, keep kosher, etc. Why do it if we don’t believe in a personal God, an afterlife, a God that answers prayers, or that following God’s commands brings us righteousness and forgiveness of sins?
That’s because Jews don’t base their religion on death. We base our religion on life. God is not about death or promising us an eternal tomorrow, but giving us a life now that we are enjoying today. You have life today, don’t you? Isn’t that miraculous that you even exist, you personally?
Jews see that as evidence of a greater Power, a more powerful Source we call “God.” What God is, we cannot say. But we don’t worship God because we are afraid that we won’t get an eternal tomorrow. We worship God because God has given us a today. Isn’t that enough of a miracle?
Is the reality and miracle of life today a trick? Sure. Some religions believe and promise and afterlife. And the Jewish sages talk about a “World to Come,” but no one knows exactly what is to really come, if anything. We only have now.
So be grateful to that Something Greater that gave you this now. This may be all you get. If you are so overcome by the fear of death that this is the only reason you will worship God, then you probably won’t get the reward of eternal life from God even if there is one if that’s the only reason you are doing it.