Arsenal can be proud of their unbeaten record in the last 8 matches in the Premier League, It's a great achievement for Arsenal after starting the season so badly. Arsenal began to experience changes when they beat Norwich, after that Arsenal's performance began to improve and be consistent. But at the beginning of the season Arsenal were beaten by Chelsea and Man City without being able to score goals, this is proof that Arsenal have difficulty developing the game when facing a big team. Moreover, Liverpool's defeat against West Ham was Liverpool's first defeat in the Premier League this season, then like you said Liverpool players must be very motivated to beat Arsenal. This will be one of the toughest matches for Arsenal, but if Arsenal can at least make the game end in a draw, it's been a very good result for Arsenal.
I didn't know they were doing good at all. I wasn't checking them to be honest and I do not wager on their games most of the time so I didn't know if they were winning or losing, never cared. After reading here I was like "HUGE RISE??" then I checked and Arsenal is 5th right now in the league. That is a serious achievement and I have to say they are really doing better than I ever expected.
Hopefully they will continue their success, premier league needs more teams to fight for a title aside from Liverpool and city. United, Chelsea, arsenal all trying to win something would mean that there would actually be some entertaining football that actually means something in the end.