Faith should be basd one reason of some sort, at least I think so.
Given the fact that "God" did exist, how could it have existed at all just by itself, and why?
Some scientsist theorize that some things just "are", that the possible singularity that started the big bang just was because we can't apply the notions of existence that we have from the CURRENT univers to what was there BEFORE it got started.
Augustine theorize the samething in regards to God, He just was always there and outside what OUR known univers views as time and existence.
You can apply the laws of nature to something that was before those very laws came to be, to which those laws to not apply.