“Envy will hurt itself
Let yourself be beautiful”

Gabrielle Aplin – The Power Of Love Lyrics on LyricsMode
Envy is when you are jealous and that can lead to very bad things, so to be beautiful, you would have to have no envy so that you could be nice, kind, pretty, handsome, or friendly! All of the good things! I think that this line can actually tell people that you should never be jealous and should always be respectful to one another.