anyways, natural science deals the the our natural senses: what we can see, touch, hear, taste, and smell. debate away all you want in that realm - there are plenty of ways to measure and prove/disprove things in the natural sense.
faith has to do with the exact opposite: what you can't see, touch, hear, taste, smell. there are no "natural" science methods for measuring the existance/non-existance of things in the non-natural realm. plain and simple.