So every person and employer would then be at liberty to decide on a whim the marital status of each employee for purposes of providing insurance and other spousal benefits? A Catholic employer doesn't have to recognize the marriage of a baptist employee for benefits? A Methodist judge would just distribute the assets of a diseased to the children without regard to a living spouse because they were married in the Catholic Church and the judge doesn't agree with Catholicism?
As for the Catholic church and other churches. One church wouldn't have to recognize or issue a anything to someone of not their faith. Kinda the point.