Well, if you’re trying to think biblically about your marriage, it shouldn’t be a focus. That is how John Piper explained it recently:
The word “biblical” in this question is perhaps intended to take me to a text. And of course the text that comes to mind is, when it speaks to beauty, 1 Peter 3:3: “Don’t let your beauty be the outward beauty of the wearing of gold, and the braiding of hair, and the wearing of clothes.”
It doesn’t say “fine clothes.” It’s just “clothes,” so you know it’s not an absolute, as though not wearing clothes is good thing. It means the jewelry, the hair, and the clothes are not the focus. And our culture needs to hear that unbelievably. Marriages need to hear it, men need to hear it. That’s not the main focus of beauty. The focus should be the inner spirit.
So women should ask, “What kind of spirit should I cultivate for my man?” as well as, “How should I eat and dress and exercise for my man?” And the man should do the same: “What kind of inner spirit makes her flourish?” because there is a kind of spirit in a man that kills a woman or frightens or bores her.
And a man shouldn’t mainly be pumping iron. Because, frankly, most women could care very little about what their husbands look like, unless they’re just making fools of themselves. They want a spirit, a strength, a humility, a nobility. They want someone to pick them up and sweep them away.
In their worst moments women don’t look at pornography, usually. Mostly they read novels about exciting romances, because their husbands are so boring!
And so it cuts both ways. I think we husbands should labor not so much with the outward man, and the women shouldn’t labor so much with the outward woman. Rather, we should all cultivate the kind of beauty that we all deeply long for in relationships.
A marriage is a relationship. When you’re old, gray, wrinkled, overweight (or underweight), squinty, bent over, and hobbling along, maybe you’ll be holding hands at 85 because of the inner beauty.