The Spanish side are considered underdogs as they face Bayern Munich in a mouth-watering Champions League quarter-final on Friday (14.08.20) but Vidal has warned that they will provide stiffer opposition than Bayern's domestic rivals.
The Chilean midfielder said: "I understand the pessimism but we are the best team in the world. The problem is that we don't always show it.
"Bayern will be confident but they must know that tomorrow they're not playing any old team in the Bundesliga, they're playing against Barca.
"We have Leo [Messi], we have the best players and we want to prove ourselves."
Vidal, who played for Bayern before moving to Barca, also backed Lionel Messi to outshine Bayern dangerman Robert Lewandowski.
The 33-year-old star said: "Lewandowski is extraordinary, very dangerous, an insatiable goalscorer.
"It's going to be very difficult to stop him but it's impossible to compare him with Messi, who is from another planet.
"But you could say that Lewandowski is the best striker in the world alongside Luis Suarez."
Bayern manager Hansi Flick insists that Messi isn't Barcelona's only threat.
He said: "Messi has been the best player for several years now. An exceptional player.
"But it's not just Bayern against Messi. It is Bayern against Barcelona. Messi is a world-class player and we have obviously thought about how to play him.
"We need to do it as a team. It is important to play smart against him. To see the spaces and put him under pressure in the one-on-ones and win those."