Neymar is confident the 3-0 defeat to Juventus can be overturned.
The second leg of the Champions League quarter-final is at Camp Nou on Wednesday evening.
“We have to believe that we can do it,” Neymar told Canal Esporte Interativo.
“The other day my father told me something and it really stuck in my head. I think it’s absolutely true. He said it doesn’t matter which team we’re facing, the fact is we are always Barcelona and that doesn’t change.
“That means we can do it. We did it once and we can do it a second time.”
Paris Saint-Germain had won their first leg 4-0, but were beaten 6-1 with the last kick of a thrilling Round of 16 tie.
While that was a huge achievement, Juve are much stronger defensively than the Ligue 1 giants.
“We have to give everything we’ve got. If all goes well, there will be another remuntada,”continued Neymar.
“I believe in this team and in our potential. We’ve got nothing to lose and everything to gain. We have to step on to that field and do our best.
“Of course, it’s going to be very difficult, as Juve are a great team, very well-organised and it’ll be tough to turn this around. We’ll have to run twice as hard.
“It remains the same chance we had last time against Paris Saint-Germain, which is we have a one per cent chance of qualifying and the other 99 per cent is faith, hard work and – God willing – the goals will come.”