Sigurdsson scored twice for Everton on Tuesday, as Silva's side beat struggling Cardiff City 3-0 to claim victory following three consecutive defeats.
Premier League title contenders Liverpool are next up on Sunday, and manager Silva believes the Toffees' top scorer will now find his best form after a run of poor performances.
"All of you are seeing a different Sigurdsson this season," Silva told the media.
"You will see, in the next match against Liverpool, Gylfi playing with more confidence."
Everton lost nine of 14 league matches prior to the trip to South Wales, with that run having started with a last-gasp defeat to Liverpool at Anfield in December, when Jordan Pickford's calamity enabled Divock Origi to score.
Silva now wants the victory over Cardiff – which was capped off by Dominic Calvert-Lewin late on – to act as a platform heading into what could be a crucial game at the top.
"We hope this is a turning point in our season," Silva added. "We have missed consistency in our team.
"It was important tonight that we won the game to give us the confidence. Sunday, we will be at home with our fans."
15 - Gylfi Sigurdsson has scored 15 Premier League goals for Everton since the start of the 2017-18 season, five more than any other player. Leader. pic.twitter.com/MmWoH2SAS3— OptaJoe (@OptaJoe) February 26, 2019
Everton had to wait 17 days to get back in action following the 1-0 defeat to Silva's former club Watford, but after Lucas Digne had ensured Phil Jagielka's early error did not prove costly, the Toffees took control against Neil Warnock's Cardiff.
Sigurdsson slotted home shortly prior to half-time before doubling his tally midway through the second half.
"You shouldn't concede the second goal which is like a Sunday League goal," Warnock told a news conference.
"There were mistakes from our point of view. But that's what happens at this level. If you make mistakes, you get punished, and we were.
"With ten games to go, we've still got a chance [of survival]. It's up to me now to make sure that we play the right team and have a go. We've got a lot of character and we won't give in without a fight."