I don’t have faith. There are things I believe, things I don’t believe, things I don’t know and I have varying levels of confidence for each belief. Everything I believe I have evidence to support. “A wise man apportions his belief to the evidence”, as Christopher Hitchens said in summary of David Hume’s rather excellent essay. Faith, alternatively, is what we call it when a belief is held outside of the confidence intervals given to us by the evidence.
If I believed that tomorrow gravity would just turn off, and acted accordingly by tying everything I own down, you might ask me why I believe that. I would have no evidence that my belief was true; it would be an issue of faith. In fact, I see this all the time in religious discussions from the religious people and they don’t realise they’re doing it. Do you remember the spoof-deities atheists used to shoe-horn into conversations and then claim to believe in: the Flying Spaghetti Monster, the Invisible Pink Unicorn, Russel’s Teapot? Often, religious people asked why atheists claimed to believe in these things, and some pseudo-logic about gravity and pirates was occasionally recited, followed by “you’ve got to have faith”.
I don’t mind you having faith. If you accept that it is faith you can probably see why I don’t accept it or care. You can probably also see why it doesn’t belong in the political sphere, if it’s unsubstantiated faith. But if you’re going to tell me that I have faith, I am going to have to ask you what I have faith in; what premise do I accept that is not supported by evidence?