Atheist in a Christian World

I am an atheist. I want to scream it from the rooftops, but that wouldn't go over too well, would it? The word has such a negative connotation. People think I am evil. They think atheists are devil worshippers. Why are people so afraid of someone who has different beliefs than they do? I understand why people believe in a god. I really do. It's comforting. It is nice to feel like things are out of your control and that there isn't anything that you can do to change it. I wish that I could feel that way sometimes. There are several things that I just don't understand about people who believe in a god. I think the first one would be why do you go to a hospital when you are sick. Why not go to church? When my kids are sick, the first thing I do is take them to the Dr. If I truly believed in a god, I would just pray to him, the all powerful, and he should be able to take care of the illness. I personally believe in science. I believe in medicine. Praying isn't going to make an infection go away, antibiotics do. I believe in evolution. I can't reconcile that one "man" made all of us. It doesn't make sense that when there was the great flood and Noah and his family built the ark and all of that story, then that would mean that we are all from Noah and his family since everything else was annihilated due to the flood, right? But there is a rainbow of colors that people coem in, so we all couldn't be decendants of Noah's now, could we?