The Hornets face a vital match against relegation rivals Newcastle this weekend and the Italian coach is proud of his "unbelievable" team, despite their lowly league position of 17th place.
Ranieri said: "I believe in this team and I'm sure at the end we will be safe.
"When I say I believe in my team, I saw in the training sessions, they work so hard, and if you continue - with luck - to fight, to believe in yourself, sooner or later you will win. That is important, that is what my experience tells me.
"I say to the players we have to continue, because it is sure, if you come to watch, the training sessions are fantastic. I have a lot of experience and I say this team will be safe. It is unbelievable our position, it's unbelievable."
Watford have lost their past six Premier League matches and there has been speculation that Ranieri's position as manager is under threat, but the veteran coach insists that he has the support of club bosses at the moment.
He said: "The club believes in me, don’t worry.
"I have had assurances when I spoke with the board, with the chairman, with everybody and we are all together. It’s a fantastic group."
The club have brought in three signings so far during the January transfer window and Ranieri hopes that the new additions can play their part.
He said: "I remember in the last match against Spurs in the Premier League [a 1-0 home defeat], we were focused in that match, we were very solid, and now I have new players, three new signings, and I'm very happy with the team.
"We must stay together and fight in every second of the match."