If you use the uncaused cause theory to try to prove the existence of god, you get stuck in a logical loop like slacker is talking about.....if everything has to have been caused or created by something else then it is a never ending chain....if something created the matter present at the big bang, then something would had to have created that something and something created that something to infinity.
If you accept that something could have just allways existed, then why not the matter itself? What if the uncaused cause (or god) is the matter, itself? Wouldn't that make everything god?