I think Matt would classify you as a soft atheist. My personal view is that one can indeed not be sure either way. Matt says no, and that kinda gets my craw...because he's presented many brilliant arguments (true, some not so brilliant IMO). No one can make any statement as being true or false without proper testing and retesting...and there is no test to determine the existence/nonexistence of God. At least not yet. When we advance far enough to understand physics fully (a loooong way off, IMO), we may discover the formula of proof/disproof.