I've been thinking, off and on, of something I once read: The purpose of marriage is not happiness but holiness. Never having been a "good" Christian despite my many attempts, I couldn't understand this line of thinking. Having been raised Catholic, I understood "holiness" to have as one of its main ingredients suffering—and why even want to get married if to be successful at it means to suffer?
But these words never left me, bobbing up every now and then from the flotsam and jetsam of my brain. Until, one day, it dawned on me what the statement meant for me. On that same day, I also realized that I do want the gift of marriage. In fact, that is my Christmas wish this year.
My view is not a biblical view, but I don't think it strays too far from it. To be holy is to be set apart from others, as God is, in his perfect goodness and righteousness, in his perfect love (yes, this is biblical; yes, I know I said I wasn't looking at it biblically).
The way I'm seeing this now is that the purpose of marriage is to perfect your love—and there's a lot of work that comes with that: work you do on yourself, work you do for the relationship, work you do to love the other properly.
Perfect love is unconditional love, and in the past I only understood that to mean you love the other anyway, but now I see better that it means your life (your success, your joys, your everything) is not contingent upon anything that has to do with the other.
The other is free to be, free of the burden of you, and yet loved by you. That is perfect love, the kind of love that is set apart.
Happiness, though not the purpose, is the byproduct.