Marriage has evolved over time. If it didn't, then it probably wouldn't be around any more.
Examples:
-Inter-racial marriage was once illegal in the US. Now it's not.
-Marriage was used as a tool to forge alliances between royal families in Europe. Now it's not.
-In Europe, it was once common for a bride's family to pay a dowry as a part of the marriage agreement. Now it's not.
My point is that elements of our collective cultures evolve all the time. The concept of marriage exists to serve culture that it's a part of, not the other way around.
Examples: -Inter-racial marriage was once illegal in the US. Now it's not.
-Marriage was used as a tool to forge alliances between royal families in Europe. Now it's not.
-In Europe, it was once common for a bride's family to pay a dowry as a part of the marriage agreement. Now it's not.
My point is that elements of our collective cultures evolve all the time. The concept of marriage exists to serve culture that it's a part of, not the other way around.