Here is an exciting (Biblical) definition of marriage from So Much More by Anna Sofia Botkin and Elizabeth Botkin:
"Marriage is about dominion. It's about filling the earth and subduing it. Marriage is about two people of different abilities and roles becoming one flesh, sharing one life and one vision, so that the two will complement each other and complete each other....Marriage isn't where your ministry stops so that you can play house and play family. Marriage is where your new ministry starts, where you become, in a sense, the queen of a little kingdom where you rule with your husband as God's vice-gerents, working together extending the kingdom, subduing the earth, properly managing its resources, and discipling the nations."