First thing I think that needs to be addressed is this idea of "indisputable, scientific, hard evidence." Can one give such evidence to anything? The answer is absolutely not. Everything can be disputed. Secondly the idea that you present that Christianity is the only faith through the title of the thread is a little odd. Why are you singling Christ followers out but then turn around and ask for a logical argument to believe in "a god" and "a faith?"
So before I just go and rattle off a standard argument from the library of apologia I'd like to know a little more about you. What do you believe, if anything? Do you think that good and evil in fact do exist? Are you in disbelief about any higher power or is it just the God presented to you through the modern day church? Have you read much on the subject or just shooting out questions? I also ask where is your hard evidence that God does not exist?