The defender scored twice in this afternoon's 3-0 win over Cardiff City at St James's Park.
Ayoze Perez also found the net in the win, which followed an FA Cup victory over Blackburn Rovers and lifted the club out of the Premier League's relegation zone.
"The team was playing with confidence, energy and intensity," said United manager Benitez. "It has been a good week, and hopefully we can carry on.
"We have to stick together to the end."
Schar opened the scoring in the 24th minute with a superb goal after running almost half the length of the pitch.
And the 27-year-old, signed for Â£3million last summer, got the final touch after Jamaal Lascelles flicked on a second-half corner from Matt Ritchie.
Benitez said: "I have said always it's not a question of a lot of money – it's a question of doing things right at the right time.
"He's a player who came to help, and obviously he's helping a lot. He has a lot of confidence in himself – that's the main thing. He knows his ability, and then he has a lot of confidence.
"When he's not playing, obviously he's not happy, but when he's playing, he wants to show the quality and the confidence he has."
Meanwhile, Benitez again refused to talk about the transfer window.
"I'm not talking about the transfer window or the takeover," said United's manager. "I cannot control those things."