Marriage is not an institution. It's a relationship.

Mack talking with Jesus ...

Jesus: "I don't create institutions -- never have, never will."
Mack: "What about the institution of marriage?"
Jesus: "Marriage is not an institution. It's a relationship." Jesus paused, his voice steady and patient. "Like I said, I don't create institutions; that's an occupation for those who want to play God."

-- from "The Shack" by William Paul Young