I tend to believe that the cause of divorce can relate to many things, but the most common (at least among my family and friends) are:

1) Miscommunication

Arguing over silly things that really make no sense. Not being patient with one another or trying to see things from another's point of view. Getting angry quickly because you feel comfortable doing so, causes hurt feelings that will re-surface later on.

2) Lack of Interest

A lot people let themselves "go" after getting married. That's not to say that a woman who has had children should look like she did when she as a teen-ager, that's ridiculous (and to those men out there who aren't appreciative of their women after child-birth, you don't deserve to have her), but I do believe that you should make an effort to give yourselves a night out together, go on a date, spend some alone time outside of the home. That gives your wives motivation to dress up and look good for you, and well, you should do the same. (Would it really kill you to change your darn shirt?!)

3) Fear

I know it sounds like an excuse, but a lot of people in my circle have described their reasons for divorcing as having fear that their life was over, that there was nothing "more" to do, that there wasn't anything to look forward to. This goes along with #2 above, you need to put an effort into keeping your interest, doing something special for each other, focusing on turning each other on, long after the vows have been made.

Don't lose sight of why you wanted each other in the beginning.. Whether you have kids, added responsibilities, or other things that can cause you to lose focus , there is no reason you can't make the time for each other.. no reason at all..