The only sensible response is surrender. It's time to lay down and accept reality. The fight is over, and SSM should be treated as settled law for all eternity. It's sad that SCOTUS has chosen to endorse sin, but it's the way things are and the fact is that the world is not going to end and straight people are not going to be forced to marry gay people. It's time for complete surrender.
Ok, I don't want to go too far down the rabbit hole on this, but what is the scriptural basis for the idea that legalizing sin = endorsing sin?
1 Timothy 5:20 :
As for those who persist in sin, rebuke them in the presence of all, so that the rest may stand in fear.
Voting for a sin-favorable ruling, as 5 justices did here, is the exact opposite of rebuking.
Technically Lawrence v. Texas is the sin-friendly case you're looking for, but the point is mostly moot as anyone that tries to argue in a court of law using the bible as a main defense is a joke.