Marriage certificate never turned in. must I divorce?

Quick decision made! Ordained my brother through Universal Life Church.com, next day had small ceremony at home, February 2nd, 2011! Left him February 15th, 2011, he was currently in possession of our marriage certificate and my social security paper work, to change my last name! All papers were filled out and signed, ready to be turned in! When I left him I asked if he had disposed of them, he stated he had destroyed them one week prior during a previous argument... A few weeks later after calling the county clerk to verify there was no certificate being filed, I had my brother ask him what he had done with it and he informed he had mailed them in! Don't want him to be able to come after me and my assets at a later time! Would also like to one day remarry and not be a polygamist! One last thing I don't have an address and have heard through the grapevine he moved out of state! How do I serve him in that circumstance?