Why should faith be seen as anything close to proof? Accepting it as anything more than a cop out and an admission that they don't care whether or not their beliefs are true seems a mistake. I care whether what I believe is true. I want to believe the most true things and the fewest false things. And if they don't care whether their beliefs are true, then there's no real argument to be had. One can't simply claim faith, and suffice that settle the matter. Unless one also concedes that by doing so, they is more likely accept something likely false over something likely true, and this is acceptable to said person.
After all, if you care whether your beliefs are true, you necessarily must use the only known method for properly determining truth from falsehoods, namely the rational weighing of evidence. One is entitled to forgo a functional epistemology, but in so doing they need to accept their beliefs are going to contain, on average, less truth and more falsehoods, and they must be okay with that and understand that I am not. -- That is after all what they mean by faith.
Followup: Apparently in context what I mean by 'faith' has been questioned. Apparently since a commenter can equivocate what he means when he says faith, my consistent usage is therefore wrong. So just for the information purposes, what I mean by faith is as follows (from Merriam Webster):
(2) : belief in the traditional doctrines of a religion b (1) : firm belief in something for which there is no proof
I'm sure none of you were confused, but it's best to clarify. More specifically faith as used in the context:
Why do you believe in God?
-- I have faith.
Such context is addressed above.