I am an atheist.
I used to think that believing in God or not was a choice. I admired people that didn't, and didn't care about people that did.
Not anymore. I have come to think that believing in God should have a definite answer, in the same way that whether the earth is flat has a definite answer. Sure, you can choose to believe that the earth is flat, but that's wrong. It's not a choice.
No one is born an atheist. We have no reason not to believe in God, and atheism is a state that needs effort to be reached.
I, and millions other people, have reached that state through education, scientific reasoning, logical deductions, and by just plainly looking at the data. It boils down to a lack of evidence for the existence of a God.
(God, in this piece, is the supernatural anthropomorphic know-it-all old man sitting in the sky and watching us all. There are other forms of God which can be fine.)
Now here's the thing: In today's world, I don't think this is a choice anymore. Any person who is educated, can reason scientifically and deduct logically, should reach that same conclusion. There is no excuse anymore in our hyper-connected western world with ultra-fast communication systems and access to all of human knowledge.
So when I see someone that believes in God, I see a person that hasn't gone through the the process of education, scientific reasoning and logical deducting. I have a problem with them. I can never admire such a person fully, because it signifies lack of coherent thinking. My perfect person has to be an atheist.
I don't have a problem with religion per se. Many aspects of religious teachings are great. But when the supernatural part comes in, and I am asked to believe something without any proof, then I cannot stand it. It's not a matter of choice, it's just wrong. I think of such people in the same way I think of people who believe in astrology, homeopathy, or faster-than-light-travel: they are unaware of the truth and thus choose to believe in something false.
It's exactly the feeling I have towards kids that believe in Santa.