Jaqen says to Arya

>"To be a dancing master is a special thing, but... to be a Faceless Man... that is something else entirely. A girl has many names on her lips. Joffrey. Cersei. Tywin Lannister. Ilyn Payne. The Hound. Names to offer up to the Red God. She could offer them all. One by one." 

By this, it seems that he is willing to allow Arya to use the House of Black and White for training in the art of 'giving the gift of the Many-Faced God' to kill for her own ends, but in the name of the god. It seems like it would go against his beliefs. 

Any insight?