Here are some thoughts on the Marriage Equality Decision made by the Supreme Court.
I think, eventually, this will be seen as strengthening of the First Amendment of our constitution.
I think, eventually marriage will be viewed as having two, independent parts:
Part-A - The Religious Part - If a couple wishs to enjoy the religious benefits of being married then they visit someone who is empowered to bless their union in that manner.
Examples can include a member of the clergy of their religion. Additionally (and this is the case even today) you can download a form from the Internet for most any state in the union and get yourself certified in that state to preform a religious union.
Part-B - The Civil Part - If a couple wishs to enjoy the civil benefits of being married then they visit the courthouse of the county they will be married in and apply for and receive a marriage license.
One of the side effects of this splitting into two independent parts may well be the obsoleting of something called a "Common Law Marriage".