Beauty is only skin deep, but stupid goes clear to the bone. (Source unknown)
This common expression may be humorous, but it carries some strong principles. First, beauty is subjective. After all, beauty is often in the eye of the beholder. We all know you can’t judge a book by its cover, but we often are first attracted by it. All of that to say that the exterior of an item—even people—is important, but the essential value is what’s inside.
Don’t be concerned about the outward beauty . . . You should clothe yourselves instead with the beauty that comes from within, the unfading beauty of a gentle and quiet spirit, which is so precious to God. (1 Peter 3:3-4)