It all depends upon what your faith is based. Fundamentally, Jewish faith rests on the fact that there is one G-d and he encompasses the entire Universe. It is very difficult to disprove G-d. The Universe is infinite but physical space can't be, by definition. So, there is clearly something much larger at work that we can see, feel and measure. Does that something, call it G-d if you like, cause the fall of every sparrow and every drop of rain? Who knows, reasonable folks will differ. My own personal belief, which is fully compatible with Judaism, is that G-d works smart, not hard. He created Quantum Physics and Molecular Biology and stood back and waited until we became self aware. That doesn't make G-d lazy, just efficient. Does it say that in Torah, no, of course it doesn't. But, most Jews believe that Torah is a combination of oral history and allegory. Much of it isn't meant to be taken as literal fact. It doesn't have to be strict literal fact to retain it's usefulness as a guide to life and the cornerstone of Jewish culture.<quoted text>
Every religion is based on faith, which, as far as I'm concerned, is shaky ground. You can argue that without a real Jesus, the Xstian religion falls apart. Similarly, without the existence of God, your religion ceases to be a religion and becomes nothing more than a philosophy with a set of moral codes, I fail to see the difference.
On the other hand, if your faith is based on a man who is your one and only conduit to the afterlife. That faith is ultimately doomed to disappointment. If it turns out not to be literal then your entire concept of what that man commands you to do goes up in smoke. Jebus's good lessons not withstanding, his primary message is, "Believe in my divinity or burn in Hell forever". At least that is how his followers explain it.