Ironically Faber in this novel is named after a famous publisher, perhaps to reflect the side that Faber is on - well and truly against Captain Beatty and the book burners. He is a former English professor with a great knowledge and love for literature, who comes into contact with Guy Montag and tries to educate him and steer him into supporting his cause. In this novel Faber and Captain Beatty both compete for Guy Montag - it is as if they are fighting for his soul. Through an electronic device that Faber has invented he is able to stay in contact with Montag permanently, and hear everything that Montag hears.
Interestingly, it is clear that Faber attempts to manipulate Montag just as much as Beatty does. He is open about his own cowardice and failure to act, preferring to stay safe inside his house and get Montag to do the actions he has not had the courage to do himself. Faber's character is a bit of an enigma, like Beatty's: at times he tries to help Montag think for himself yet at other times he wants to dominate him. Likewise he can be heroic at moments and other times extremely cowardly.