I APOLOGIZE FOR GOING SPOILERY ON MY TUMBLR FOR ANYONE WHO HAS NOT SEEN THIS SHOW/THIS EPISODE YET. SO I WOULD ADVISE YOU BEST TO SKIP THE ANSWER TO THIS, OR SOMETHING.
Are you sure you haven’t just seen the first three episodes? Either way, “I believe in Sherlock” and “Moriarty was real” are connected phrases. In the third episode of series 2, we find out Moriarty has cleverly set up Sherlock in a way that made it look as though Sherlock was a fraud. The cases he’d solved involving Moriarty appear to have been previously planned, and Moriarty himself was an actor named Richard Brook that Sherlock hired to appear as some kind of arch-nemesis for himself. Saying “Moriarty was real” is disputing the claim that he was Richard Brook, which is what he told a reporter and created evidence to back up. Hopefully this makes sense, but I’m sort of confused that you don’t understand and have seen all the episodes…
