We don't know that there isn't a hell, but believing because there is a threat of hell is known as "Pascal's wager", and it has been debunked so many times as bad reasoning.
The argument I like best about it is the argument that there might be a God who only rewards atheists with Heaven, and sends all believers to Hell (or Heaven too, I dunno, everything is possible). To put it simply, for every God someone can think up that sends atheists to Hell, we can think up an alternative God that doesn't.
Unless there is any direct evidence for any of these Gods, there is no point in believing one way or the other.
The argument I like best about it is the argument that there might be a God who only rewards atheists with Heaven, and sends all believers to Hell (or Heaven too, I dunno, everything is possible). To put it simply, for every God someone can think up that sends atheists to Hell, we can think up an alternative God that doesn't.
Unless there is any direct evidence for any of these Gods, there is no point in believing one way or the other.