I Promise to Put Your Happiness before Mine
Really it all boils down to this, doesn't it? You promise to subvert your needs, your wants, your goals and priorities, to those of your spouse. And he or she does the same for you. If you're both working for the other's happiness, earnestly and sincerely, then you're both going to be ridiculously happy. Here's the key though: It's not enough to sublimate yourself and be a virtuous martyr for his/her dreams to come true. You also have to allow your spouse to do the same for you. You have to be able to say "Okay!" when he says "Go!" To say "Thanks!" when she says "I don't mind!" And trust that when it's your turn to reverse roles, you'll do the very same. Because in the end, it's not even selflessness. It's working for the common good. And if you can't say you'll do that, then "until we are parted by death" is just going to be a long, dull, sad life sentence. In my opinion, if you can't wholeheartedly vow these things, you shouldn't be getting married. Yep, it's a little tougher to promise "in fatness and in emaciation, even if my mother hates you" than it is to promise "in joy and in sorrow, forsaking all others." But which is really braver, and what promise more meaningful?