there are good atheists, there are bad atheists.
Absolutely. To disagree with that would be rather ignorant of reality. Now while I realize that atheists get a very bad stigma placed upon them, this is why I hate the term atheist, it isn't atheism that is bad, rather the atheist that is bad.
I'm surprised you don't know many atheists. Many atheists are actually very knowledgable in religion. They know the bible well. They know the history of the bible and other religions well. My transition to atheism began with the faith I was brought up as, a roman catholic. When I was about 13, I really had doubts about the whole deal. It just seemed wrong. The points weren't lining up. Instead of the connect-the-dots making a Mr. Potato Head, they formed a Chevy Stationwagon. My problem was finding something I could believe in. Senior year in high school, our english teacher had us read a few chapters of the Tao Te Ching. Our teacher had a way of just babbling for a while, so I would take the whole book from his desk and read it during his babbling session. This was my enlightenment. It showed to me, morality and definition can exist without god. Then I went to a Christian college to get my engineering degree, the catholic church paid my tuition for 4 years... suckers. It was there, in my freshman year that I learned it was alright to question the bible. My first religion teacher, a brother, taught us some of the history and the real meanings of stories in the bible. This is when I fully emersed myself in the bible. I read the majority of it and had nothing but questions and then eventually made a couple of conclusions that were to be confirmed later on about the writing of the bible. From this education, I learned, as have many other atheists, about Judaism and the Christianity that comes from it. We made our conclusions that rival that of the mainstream culture. And this lends nothing to experiences in life that mold opinions.
This is where you'll run into atheists that seem to be arrogent. Some are just fed up being told that they are wrong all the time. That there is a god willing to love them if they just stop hating god. The mainstream christian's knowledge of the mind of a mainstream atheist is very poor. We aren't the satanic worshipping haters of the world. We don't sacrifice children for the fun of it. We don't have a hatred of god. We aren't being soliders of satan. We don't think science is the end all, see all of life. We tend to be well educated people, 50/50 have arrogent attitudes, the others are tranquil, we really believe we have looked at ALL of the evidence and have come to the reasonable conclusion.