I'm an atheist, but I'm wondering...?

Why do some atheists say that Christians are close-minded? When you think about it: They worship a magical creature in the sky, that apparently created something out of nothing. They believe that children can be born of virgins, that eating an apple is going to bring ultimate evil unto the world, that if you sin, and do not ask for forgiveness from aforementioned magical creature, you will spend eternity in a place of ultimate pain, torture, and heat. Well, now, I'm wondering--if you ask me, that's pretty d*mn imaginative. So, how ARE they close-minded?