If someone believes in a God then to them it exists. If it guides them in their decisions, lifestyle and deeds then that is tangible proof that their God exists.

So, lessee. "I believe in God. I believe God guides my deeds, lifestyle and decisions, so, because I believe he does that, and because I believe in him, he must exist."

Will the circle...be unbroken...?

(I won't even bother to revisit the "tangible" thang...)