Where marriage is a sacred institution, the state should have nothing to do with it. Each church should be able to do as it pleases. On the other hand, to the extent that marriage is a secular domestic contract between two people, there can be no justification for discrimination based upon the genders of the parties.
The States of California, Hawaii, New Jersey, Oregon, Massachusetts and Vermont have recognized this and much of Europe to an even greater extent. Connecticut, New York and Rhode Island have just become the sixth, seventh and eighth states to recognize domestic partnerships and provide gay couples with the benefits that the married enjoy. The only hitch is that they have to travel to Massachusetts to get married.
http://home.hvc.rr.com/uucrt/for_better_or_for_worse.htm http://www.andrewsullivan.com/homosexuality.php and http://juandejesus.50megs.com/gayissues.html