Former Tottenham boss Sherwood arrived at Villa Park in February, and has since led the club away from danger in the Premier League, as well as guiding them to the last four of the Cup.
Villa are now six points clear of the relegation zone, and are eagerly anticipating Sunday's semi against Liverpool at Wembley.
"The first day he came he said we have to play without fear," Benteke told the FA's official website.
"You can see when he speaks he has a lot of charisma and confidence and it helps because we are a young squad.
"It's not only me, but it's all the squad. When he arrived he gave a lot of confidence and feeling. He has given us a lot of freedom.
"Not just me, but I think Gabby [Agbonlahor], the other strikers and the midfield, he has helped us a lot."
Benteke has been in superb form in recent weeks, netting eight goals in his last six league outings.
"We strikers live by goals. A striker who doesn't score can't properly help the team because he has to score goals," he added.
"When you play in England you have pressure every week. You have to deal with it and for me it's ok.
"Before the gaffer came, I was sometimes playing good but didn't really get many chances, and I'd go back home frustrated. It was mixed feelings, I'd be frustrated because I didn't score and because I didn't have chances - now I have chances.
"Everyone is motivated to go there [Wembley] and try and do something good and get to the final.
"At the moment the confidence in the team is high. We can't just be happy to play in a semi-final - you want to go to the final. So we will fight like we have done the last few weeks."
