Staceyboo;
Lets look at all the peoples and cultures that history can tell us about.Or that you can conceive of.
How many cultures can you say do not believe in an after life.
I would say that I cannot think of 1 except in the modern age of industrialism.

Why would industrialism not want to believe in the after life?
It wants all your focus on producing here and now so the capitalists can continue to make great gains.
Greed says: "get it now because this is all there is."
So your statement "find it hard to believe we just die" is a good one and a good start.

Just MY OPINION.