Heaven knows, I've done my fair share promoting the marriage of convenience which in Dutch is called the marriage of understanding (as in using your brain while choosing the future marriage partner) however, I'd like to stress that in Western Christian tradition marriage has always been considered something more than a mere trade deal.
When you say, "I do", you create something which has been considered very special from the time immemorial: what God hath brought together let no man put asunder. You create a new family which originally consists of the husband and the wife and later (hopefully) of their children, too. The Scriptures speak highly about marriage and point out that the relationship between the spouses is more important even than the ties between grown up children and their parents:
Therefore shall a man leave his father and his mother, and shall cleave unto his wife: and they shall be one flesh. (Quoted from here)
Nowadays this very basic family unit is under assault from all directions. While many Christians get upset about the acceptance of alternative family arrangements like SSM, they often conveniently forget to mention the scourge of easy, no-fault divorce and its wide acceptance both in church and society.
While I think that divorce should not be entirely prohibited, it should be, in my opinion, restricted to certain extreme cases, fault should be proven in court and the other spouse should be able to contest it. As of now, the one who wants a divorce will always get it and the only reason people go to court is when they are fighting about custody and property division.
Divorce is the ultimate betrayal. It tears families apart and creates misery and poverty. Divorce is also oath-breaking, especially if the couple were married in church. For better for worse, till death do us part, becomes for better or never or simply until I get bored and can move on. I'd like to point out that our Germanic ancestors even in pre-Christian times considered oath-breaking one of the most despicable crimes, worthy of torments of Hell. (More on this topic here)
Marriage bond is meant to be the source of comfort for the couple, so when the life gets tough, they can support each other, instead of choosing an easy way out. No-fault divorce creates a situation when spouses start distrusting each other and even suspecting the worst, especially if someone in their circle of family and friends recently got divorced.
It's often especially devastating for the homemaker, who is left without means and forced to search for a job, which can be quite challenging if one spent years at home. Women have always competed with other women for resources which they primarily got through men. Even in our progressive times, most women still rely on their husbands' paychecks to make ends meet and easy divorce takes away any security they can have in their marriage. I'm convinced that no-fault divorce is the greatest threat to the traditional family which exists nowadays.
The other way the marriage bond is attacked is subtle and less obvious but nevertheless, it's a direct assault on the husband's position within the family. Gone are the days when the man was the king of his castle and his wife bore him children. In those days she used to be a housewife/homemaker nowadays, if she stays home at all, she is a stay-at-home mom or a queen bee. It's all about her and her children and the husband exists to function as an ATM and give her foot massages.
Childless couples are often denigrated and the idea that a woman whose children are grown should stay home for the sake of her husband is ridiculed or never even mentioned at all. In fact, I personally know someone who was once told by a church lady that she had no family since it was only her husband and herself at the time. The fact is that your husband is your family, he will stay with you after the children have left home and he doesn't like to feel that the only thing you need him for is his paycheck.
I know that some folks on the right are very cynical about the whole concept of romantic love, and I myself criticised it on this blog and pointed out that "love" alone was an insufficient reason to get married, and yet, the concept of finding your Prince Charming, falling madly in love and living happily ever after persists in Western culture, the only culture in the world which enforced strict monogamy and thus raised the wife to the equal social standing with her husband and created the notion of marriage being more than just a business deal between familes and an instrument of getting a legal heir.
You may call it emancipation, I call it degeneration