Perhaps I do. Certainly it's true that longitudinal surveys show increasing percentages of the population in Western countries (even the U.S.) self-identifying with some sort of nonspecific "spirituality" rather than with any specific religion.
Identifying just what that implies and what they actually believe, though, is a tricky thing. It often seems like kind of a catch-all category — people expressing some equivalent of "I know there's something more out there, or at least I can't give up the hope that there is, but I just don't know what and neither do any organized religions."
I certainly don't dismiss mental and emotional wellbeing as unimportant or not useful. I just place a high value on achieving it through methods grounded in truth, to the best of our ability to determine it... or at least, not grounded on the shifting sands of fuzzy supernatural thinking. Moral philosophy, as I and others have commented, can and does offer a foundation for a life of principles and values (and, I submit, one's principles and values should be logically consistent), without the need for any supernatural or "spiritual" aspects.
That said, it doesn't necessarily preclude such aspects either. But that leaves the question, as does your entire post... in the absence of any specific religious doctrine or schema, just what is this faith in? For you, personally, what does it involve? What does it add that philosophy alone cannot provide?
Well, technically you're correct. Through 99% of human existence, our species got by without science. Of course, life tended to be nasty, poor, brutish, and short, and we didn't understand the vast majority of what was going on in the world around us, but technically we didn't go extinct. So that was all hunky-dory, right?
