Hazard is yet to make an appearance for Madrid this season, having suffered a muscle injury just as he neared a return from an ankle issue.
The playmaker struggled to have much of an impact for the LaLiga giant in his first season following his arrival for a reported €100million (£86m) from Chelsea last year.
But Belgium and Madrid team-mate Courtois believes it is only a matter of time before Hazard delivers at the Santiago Bernabeu.
"Hazard? I have no doubt, I am sure we will see the best Eden Hazard," the goalkeeper said.
"He is the first with the desire to show it. I see him very well and hopefully soon he can prove it.
"Just before his injury, he played several games very well and there he had such bad luck and getting out of that was not easy.
"But now this month I saw him train very well. I am sure that in no time he will explode and will to give many joys to the team."
Courtois arrived at Madrid from Chelsea in 2018 and also struggled initially, but he has turned his form around.
The 28-year-old paid tribute to coach Zinedine Zidane for continuing to back him.
"Zidane has given me a lot of confidence. I have always felt that he counted on me and it is important," Courtois said.
"In those difficult moments at the beginning of last year, if you don't feel that the coach is with you, it becomes difficult."
Courtois' save percentage in LaLiga in his first season with Madrid in 2018-19 was 65.4, as per Opta.
That figure improved to 79.2 last season, as he faced 302 shots in both of those campaigns.
In four games so far in 2020-2021, Courtois' save percentage is at 86.7, showcasing his improvement at Madrid.
Madrid, which is top of LaLiga with 10 points from four games, hosts Cadiz on Sunday (AEDT).