People may say all sorts of things, throw around the words love, forever, for better or worse, and maybe they truly intended them, but they can’t actually guarantee them. “Until death do us part” is the only thing that’s a certainty in a relationship, romantic or otherwise.
Can you please explain why “Until death do us part” is different from the other words (forever, for better or worse, etc.). To me they all mean the same thing which is forever on this earth. “Until death do us part” is not a guarantee either, as in the case of divorce.