My wife asked me the same thing. I thought about it for a moment, and told her it was a great question, and I was glad she asked me. I then told her "Several reasons.
1. Because I take vows seriously, and I made a commitment before God to honor you;
2. Because I don't want to teach our children that when things get tough, you cut and run;
3. Because I loved her;
4. Because I didn't want to go to my deathbed with regret that I didn't try to do everything I possibly could to try and save the marriage;
and
5. Because if the situation were reversed -- say, I had a drinking or a gambling problem or something -- I would hope that you would do the same thing and fight for me.
