Oh, please!!!! You are terminally naive.
Why? If states send marriage to the feds, the states can't be forced to marry anyone. They don't do that anymore. .The churches have a ritual called Holy Matrimony - like they do communion. It's what they do in a church. It's the product they sell - the only product they sell. If a member is of good standing according to Biblical teaching, that member can be given that one specific ritual. If the Luciferions don't like the only product this institution has to offer, they can to go to an institution that sells their Satanic stuff or go to the feds for their doctrines.
The law can tell Americans WHO they must serve, but can't tell Americans WHAT products they have to offer. They can't tell a motorcycle dealer he MUST sell vanilla cupcakes! If homos want cupcakes, they'll have to go somewhere else.