It's got very little to do with faith and a lot to do with some pretty workable thought control techniques that Hubbard spent decades working over. That's my two cents.
But, it has a GREAT DEAL to do with "faith".
Faith means "belief in things unseen". It means to have a certainty about that which you actually have no experience and no direct observation of. That is why people have "faith" in God - because it is based almost wholly on belief, and upon ZERO personal experience of anything tangible.
In Scientology, the indoctrination system produces FAITH about all sorts of things. It is very much the same as with other religions, in that the follower believes in things that cannot be seen, experienced or shown to others. It is entirely subjective. But, the contents of the subjectivity follows an exact pattern defined by Hubbard's nomenclature and paradigm. The group shares the same set of ideas.
Of course, Scientology will NEVER present itself as being based on such a high degree of faith as a way to "prove" that it is a "religion" (like other religions), because that goes against so much of Hubbard's claims that Scientology rises above such nonsense and is based on actual "research".
For example, there are no actual OTs with any sort of abilities as defined and described by Hubbard. Nobody has ever SEEN ONE because they don't exist. Yet, many Scientologists BELIEVE that such states exist. They are quite certain of it. THAT is "faith". This involves believing in things that one has never experienced anywhere at any time.
Continuing along, Scientologist BELIEVE that Scientology possesses a certain road to spiritual freedom. Scientology doesn't possess any such thing, but the followers have FAITH that it exists. This is the same as believing in God - there is NO evidence anywhere at all, yet the followers choose to believe.
This is especially ironic because Hubbard tells newcomers that they don't have to believe anything at all. They only need to try Scientology and see that it works. Except that they end up coming to believe in a great many things that have no evidence.
Scientologists believe that Ron is working hard at Target II, preparing the future Bridge for them. There is no evidence of THAT. It is a belief - held with "faith".
Scientologists believe that DM and RTC have guaranteed the "purity" of the "tech", and that RTC has ensured the availability of the upper OT Levels. Except that there was no OT 9 and 10, and various Sea Org staff "put it together out of nothing" (if they put it together at all). Scientologists believe that Ron created and left a fully complete Bridge to Total Freedom. Except that he didn't. Yet they BELIEVE so with FAITH.
I could go on with hundreds of examples.
There is a tremendous amount of "faith" in Scientology. It is never presented as "faith", and followers are tricked into developing such faith. They never CALL IT "faith". They call it "certainty". But it is the same thing; belief in things without any evidence or even despite contrary evidence.
This is just another of the great many contradictions in Scientology. Hubbard tells his followers over and over that there is no need to ever believe anything in Scientology, and that it is based entirely on "workability" and "scientific technologies". Yet, in the end, Scientology participants come to accept and believe a great many ideas. With FAITH!!!! The deluded dummies call it "certainty".