This paragraph from Richard Dawkins explains better than I could why I think faith is immoral:
"anybody who once believed in the religion and no longer does needs to be killed -- that clearly is evil."
Now wait a minute. Wait, wait, waaaaaaaaaaaait!
How can he, you, or anyone talk about the terms "evil" or "immoral" without beliving that we are subject to a set of standards outside of the bounds of our own logic?
What if "evil" to one man is not "evil" to another man? The 9-11 hijackers didn't think it was "evil" to do what they did. They thought it was the right thing to do. And they can give reasoning and justification for why they thought it was the right thing to do.
Who's to say that this fellow's idea of what is "evil" is any more "right" than theirs?
And if you say to me that most rational thinking people just know that it's wrong to murder people, then, I say to you, what of the "ad populum fallacy?"