Actually I do have a big background in science..  You are correct that the Universe is highly improbable.  I do, however, live in it, so the evidence that it exists is overwhelming and I cannot ignore it.  Therefore, based on the evidence, I accept that the Universe exists.

If God (however improbable) were to provide some evidence of existence, then I would reconsider what I believe.  Until such a time I will operate under the assumption that there is no Gods.

Cheers!