Last week’s 4-1 defeat to West Brom was their third loss in eight Barclays Premier League matches at Goodison Park and their fifth overall.
Having taken just 16 points from their opening 15 matches the 16th-placed Toffees are 10 adrift of Manchester City in fourth.
They have won just one of the last seven — that against Stoke on October 30 — but last weekend’s humiliation against the Baggies has convinced Moyes things have to change.
“Sometimes you get knocks,” said the Scot, who will mark 400 matches in charge of Everton at Chelsea today.
“I started this season thinking it was my best-ever chance— even better than the year we finished in the Champions League places — of being in the top four positions.
“At the moment it is not working out that way so I have to change and make sure I get a team that at least gets back to showing they have got a bit of fire in their bellies.”
Moyes, who has been at the club for nearly nine years, becomes only the third Everton manager after Harry Catterick and Howard Kendall to reach 400 matches.
But landmarks mean nothing to the Scot, who is desperate to bring some silverware to the club.
“I really want to be successful with Everton,” he added.
“That has been my goal and I am driven. So many people said when I took the job ‘you’ll never turn Everton around’ and it drove me on.
“It has been my inspiration to say ‘I will prove you wrong and I will show you’.”
Moyes could be without defender Phil Jagielka today after he picked up a knock against West Brom, while right-back Tony Hibbert is definitely out.
“We have a bit of a doubt over Phil Jagielka and we will have to see how he is,” said the manager.
“Tony Hibbert will definitely miss the game. I don’t think many people realise but he suffered a really bad cut to his ankle early in the West Brom game and had to be stitched up at half-time. He did really well to carry on for us but he won’t make it tomorrow.”
Mikel Arteta starts a three-match ban but fellow midfielder Marouane Fellaini returns from suspension.
“I have had a frustrating time. I was injured then I got back training again, I played again and then was sent off,” the Belgium international said.
“It is hard at the moment because we haven’t got enough points, but we start again at Chelsea and hopefully we can get something there."