Bale has scored six goals in his last six matches in all competitions. The Wales international initially struggled on his return to Tottenham from Real Madrid on loan.
Bale has now started the last three league matches which Spurs have all won.
"They look a different team," Scholes told Premier League Productions.
"The threats they've got in those forward areas, as good as anything in the league really. Just behind them is probably the problem.
"If you keep him fit as I said before, the quality he's shown throughout his career, at Real Madrid okay he's been quiet the last couple of years and hasn't played a lot of games, hasn't played a lot of football.
"But he's looking fit, he's looking sharp, it's not just his goals but it's his quality he brings, great left foot, switches the play at times. He's brilliant and he's got a lot of confidence.
"I think if Tottenham are going to finish in the top four, he's going to have to have a big part to play and he's got to stay fit."