Professor Reno persuasively argues that removing all religion from the political arena actually reduces liberty:

In other words, in the old system, the state presumed the existence of a substantive, natural reality that required legal adumbration: the union of a man and a woman, and the children resulting from their sexual relations. Now the Canadian government sees that it must intervene and redefine marriage and parenthood in order to give fixed legal standing to otherwise fluid and uncertain social relations. When the gay friend donates his sperm to the surrogate mother hired by a lesbian couple, the resulting “family” is a purely legal construct, one that requires the power of state to enforce contracts and attach children to adoptive parents.

The result is the opposite of the libertarian dream of freedom. As Farrow observes, with gay marriage we are giving over the family to the state to define according to the needs of the moment. The upshot, he worries, will be a dangerous increase in the power of the state to define our lives in other realms once thought sacrosanct. “Remove religiously motivated restrictions on marriage,” he writes, “and it is much easier to remove religiously motivated restrictions on human behavior in general, and on the state’s power to order human society as it sees fit.” The libertarian dream turns into the totalitarian nightmare. Who can or cannot be a spouse? That’s for the state to decide. To whom do children belong? It’s up to the state to assign parents as its social workers and judges think best.

Food for thought. I encourage you to read it all.