The States will have to only recognize marriages under a Civil Certificate.
My husband and I were living together illegally for 5 years because we did not file our marriage certificate with the state of Michigan within 90 days of the wedding. This was in the 1970's.
I lived with my husband for 2 years before we were officially (err, as per the state UNofficially married).
Now, since the state doesn't recognize religious issued marriage certificates, how do I get my license renewed?
And, by the way, this was done in our state first and needs to be made transferrable to other states. Which is what they are doing now with the 'have children proposal'. The only result they care about is having marriage recognized under Civil law and not religious.