If you think the government solemnizes marriage, then you equate government with God.
Linking marriage only with its religious source is the solution to this dilemma. If your religion doesn't perform gay marriage, then it should be irrelevant to you if some other religion does. And if government gets out of the marriage business and only administrates civil unions, then it has no way to have any effect on anyone's marriage.
Problem solved.
Are you ready to allow homosexuals to get equal access to adoption of children? Are you willing to allow polygamous relationships to share in Social Security, pension and welfare benefits?
Are you ready to have family issues resolved in the street rather than in court?
Just what would marriage look like if you and Hi Tech were in charge of overhauling the current system?