handsome 成语
handsome is as handsome does|handsome
informal A person must act well and generously so that he will be truly worth respecting.

A proverb.
Everyone thinks that Bon is a very handsome boy, but he is very mean too. Handsome is as handsome does. Compare: FINE FEATHERS DO NOT MAKE PINE BIRDS.
handsome is as handsome does
handsome is as handsome does How one acts is more important than how one looks. For example,
He may be homely, but he's the kindest man I've ever met—handsome is as handsome does. This expression already appeared in John Ray's 1670 collection of proverbs.