I have never liked the idea that faith is completely blind.
I can claim to have faith in pink leprechauns--doesn't mean they exist (And for those of you who do believe in pink leprechauns, I will be gracious to say admit that not enough evidence has been gleaned to entirely dismiss their existence.)
When I have faith, I know at some degree that something does exist, is true.
All the evidence in the world short of a concrete scientific discovery will not replace faith.
That being said, it's not wrong to be skeptical, dubious, to take things with a grain of salt, if you will. The worst thing one can do in spiritual things is to believe something just because someone says so. If you have faith in something, you have reason for having that faith, be it tangible evidence or intangible. It might not be "evidence" per say, but it's something.