I don't think people go to heaven and hell since they were used by the Church to promise peasants/workers/serfs a afterlife of "paradise" if they followed the 7 virtues (suffering here on Earth) but if they enjoyed life here (7 sins) they get casted down to hell for eternal torment. Which is the I think main point of Karl Marx's
Opium of the People comes from since if you have wasted your entire life suffering while they could have enjoyed life here on this world? What if after you die and thats it? I think this is where modern day Atheism comes from due to these points (well much more a product of western society/philosophy anyways).
While I do think however that the "having one life and thats it" model would make not only our lives but also this entire existence meaningless and our consciousness has to go somewhere...
I think I prefer being a ghost/wraith floating around the world rather than continuous activity for all eternity as religion tells me...