Well, I first was going to remain silent on the topic, but I'll bite. First, atheist and agnostic are not the same. Most atheists say firmly "there is no god" whereas agnostic is "don't know".
To iggy's points, yes I agree, that we humans do tend to judge each other, and well, I wish it wasn't so. However, to counter his point, if you neighbor tries to mess around with your wife, or kids, well now all of a sudden how they live their life is important. Religion laid the foundation for the moral codes we live by. I for one was always taught to love thy neighbor, it's a dam shame we do tend to "judge" others so much.
As far as the idea of "there is no god", well, why do you love your wife, girlfriend, family, etc.? Where did that love come from?