There has to be faith in something for the whole process to get started.
I think that where everything gets started is in some sort of experience that one regards as objective reality.
You might say, "well, a person believes
in Dharma" or something like that,
but then the definition of "believe" comes up again.
That is why I maintain that the whole question of "real or not?"
regarding what to believe and what not to believe,
from the buddhist point of view, is irrelevant.
What matters is that beings experience what they experience as objective reality.
One might read that "because of karma a being is reborn into the realm of hungry ghosts".
But what does that actually mean?
If we start talking about whether such a realm exists somewhere in the universe or in some other dimension,
that is pure speculation from a point of view based on a misunderstanding of the teachings.
Buddha didn't delve into speculations.
So, I think, as soon as we realize we are speculating, we should know we are sidetracked.
So, when various authors say "we don't need these superstitions" and so forth,
the question arises as to whether or not we need or don't need superstitious fantasies.
But it's the wrong question, because that never really came up to begin with.
When we hear that karma propells beings into this or that realm,
we have to look at our own realm, the human realm, and consider how 'real' our experience of it is.
this has nothing to do with whether it is real or not.
This can be compared to a dream state, which we experience as real.
And it is precisely because of our previous thoughts and actions
that we have the pleasant dreams and terrible nightmares that we have.
That's the point.
We can see easily how our dreams are created by our karma.
Likewise, the experience itself of the human realm, as well as the other realms, is created by karma.
So, a being is reborn, meaning the effects produced by the actions of body, speech and mind
produce a kind of echo.
The mind can go anywhere.
It can have the very 'real' experience of human, or hungry ghost, or animal, or deva or whatever.
"irrational" is only a comparative concept.
Dreams are irrational, yet we experience them as rational events, even if they are really weird dreams,
we see them as weird compared to not-weird
and this only happens because of rational mind.
So, this has nothing to do with "belief" in things we cannot see or prove.
It has only to do with our direct experience of our own minds,
and the suffering and cessation of suffering
neither of which exists outside of the mind.