My capacity for religious faith is so minimal that it's effectively absent. Some religious folks would claim that I just choose not to use faith that I do indeed have, because "it takes faith to believe that the sun will rise tomorrow" and "it takes faith to assume that the ground you walk over will hold you up." True, I don't know that the sun will rise† tomorrow morning until it actually does, but it's never missed a day in my experience. I've never sunk into any piece of solid-looking ground that I crossed, so I assume that other solid-looking ground will hold my weight. Maybe this limited sort of "faith" could be called "practical" or "empirical" faith, to distinguish it from the religious kind.
Mark Twain wrote, "Faith is believing what you know ain't so." That, like the "You KNOW It's a Myth" billboard sponsored by American Atheists last year, is probably an overstatement. Even those who question their religion's claims can't really be said to "know" that the claims are baseless. After all, they've got "practical faith" of their own; surely some of their prayers have come true! Who's to say that Uncle Joe's bum heart wasn't healed as a result of prayer (although the skilled surgical team and triple coronary artery bypass graft probably didn't interfere with the "divine healing" process), or that a prayer for a loved one's safe trip didn't prevent an airline disaster? Lab animals that are only occasionally rewarded with food for pressing a bar will keep pressing the bar even when food doesn't appear. Consistent reinforcement isn't necessary to learn a behavior, and hope is a powerful motivator. And we humans aren't nearly as rational as we'd like to think we are.
† Of course, the sun doesn't actually "rise" above the Earth; "sunrise" is the process of the sun becoming visible above the horizon as a result of the Earth's rotation. Me, pedantic? Never!