If we buy into the idea (falsehood) that there is a separation that can exist between Church and state, then this civil vs religious marriage argument might make sense. However, there is no such separation, and whatever one single person does, even in what might be felt to be total isolation, effects all of humankind spanning all of time and space. There is no separation: we are all part of each other -- one body. When people afflict themselves with death by turning from God and following their own selfish desires, the rot that they bring upon themselves tries to spread like gangrenous poison to the rest of the body in order to afflict it with the stench of its evil. We are not made to live unto ourselves. Such a state is not Life, but death. It is not Light, but darkness. It is not good, but evil. "Woe unto them who call evil good, and good evil" (Isaiah 5:20).