Do Christians really believe they will live forever?

I mean throughout most of history people have lived under the thumb of a king or dictator and religion was a wonderful tool to help them accept their unhappy lot in life. What better deal to tell your peasants than the lie that they too will live in a castle when they die. In fact it will be an even better castle than mine, with streets paved of GOLD! It is so obvious that religion was constructed for this purpose. So I ask again, do Christians really truly believe they are gong to live forever in a castle with gold streets?