In 1984 so far, Julia and Winston have ran off into hiding from the government in an apartment above the shop of a friend. Winston and Julia have become outcasts, and they are fearing the so called thought police's intrusion. Winston, in hopes of finding the leader of the "brotherhood," goes to O' Brian, an agent, and tells him that he will fight and find the leader of the Brotherhood. Julia is there, as they are a forbidden couple, but O' Brian does not know of their relationship. By the end of the meeting, O' Brian seems to have guessed the nature of their relationship.
The Brotherhood seems to be some sort of reference, possibly to the Illuminati. This would make sense, as the illuminati are illuminated in the fight against the blinded christians. The brotherhood, being above the influence of the power of the government, whereas everyone else is brainwashed, would have be considered illuminated and powerful. Also, the Illuminati's full name is the "illuminati BROTHERHOOD of the beast." The reference makes perfect sense. Also, judging George Orwell's hate for oppression, Christianity seems the perfect choice for a reference to the bad guy, seeing as how that peaceful mass-religion has nothing wrong with it on paper, but as soon as a minority comes in, (such as Julia and Winston, a minority of love) it suddenly changes for two hundred years to exclude them.
