"Do unto others as you would have them do unto you." I found this archaic version too.
and other saying : "Treat people the way you want to be treated".
It is precisely because the English has a ready made, idiomatic expression that I edited Madeleine's version, which conveyed the general meaning but which "felt" translated. A good translation is one that "feels" like it written directly in the target language.
I will add Freya's suggestion in the comments under the translation as an alternative to this rather old fashioned one.