I think, Oushi's statement, "Buddhism is not about understanding, it relies on belief in the same way as Christianity does" is not entirely accurate. In the Abrahamic tradition (Islam, Judaism, Christianity) one's faith is put to the test, and this is a recurring theme in both the old and new testament. God creates all of these situations in which doubt arises, and the human participant must rely on trust and faith. This sort of faith is not really an issue in Buddhism, except, I would say, as a method of fully letting go of what is sometimes referred to as ego clinging, and in the Pure land Traditions, as self-power.
In many of the commentaries on Pure Land Buddhism published since its introduction to the English-speaking world, efforts have been made toward identifying a distinction between faith as understood in Christianity, and "faith" as a word used to translate a sort of conviction based on one's own personal experience in Buddhism.
I mention Pure Land Buddhism here only because it is often seen, even by Buddhists of other traditions, as the most "faith-based". All Buddhist traditions share what might be called a "letting-go point". But this is not entirely the same thing as a "leap of faith" in the Christian context. Similar in some aspects, perhaps, but not identical.
In Buddhist (Mahayana) Pure land practice, especially in the Japanese traditions, all self-generated efforts at liberation are regarded as convoluted attempts by people foolishly relying on their own calculating minds. Focusing on Buddha Amitabha and one-pointedly chanting his name mantra, abandoning every other method, thus is regarded by its adherents as the most direct path.
There is a Christian bumper sticker that says "Let go and let God" which expresses that idea of faith, and I think, comes very close to describing this path as well. In Alcoholic 12-step programs, "Higher Power" however one regards that, is a similar notion. The point is that by letting go of what we are clinging to allows us to move freely, and at some point you just have to do that. It isn't a matter that the dock post is holding onto the boat, keeping it from traveling, but that the boat is anchored to the dock post. You cut the rope, the dock doesn't go anywhere. It doesn't matter any more. The boat is free.
In the Zen tradition, for example, in the Practice of Koan or riddle, if one uses one's "rational mind" (that intellectual safety net that tells us squares always have four corners and four sides) to solve the Koan, the Koan remains unsolvable. Only when we stop theorizing about apples and actually take a bite out of one do we actually have a direct realization of apples.
It is not so much an issue of cutting through the intellectual process itself, but of cutting through that clinging to the intellectual process, so that that direct seeing is realized, that one is able to really free oneself from the same habits of conceptualizing things that bind us to samsara in the first place.
In the Vajrayana tradition, deity visualization, in which complex personifications of the mind's enlightened qualities (compassion, wisdom, etc.) are first generated -- and then dissolved, is another method of approaching this. One sees that just as the reality of the visualizations are created in the mind, so is the reality of our everyday world. Mind is not abandoned, but is used to observe awareness itself. From this, a point arises when direct experience becomes spontaneous, effortless. Again, it is a matter of setting aside the way we usually go about approaching things, which is very limited, really, and allowing for a different way, something that is not limited by rational calculations, but which is infinite, to kick in.
In this sense, there is some similarity to faith, or "belief" as you describe, in the Christian tradition. But Buddhism really doesn't rely on anything one would call "blind faith". Faith in Buddhism is a matter of conviction established through practice (meditation) and constant, direct personal experience.
But perhaps, underlying it all, must be some faith in the idea that perfect cessation of suffering, buddhahood, liberation, nirvana, whatever you want to call it, that something is there that you can work towards...that this is really true. Otherwise there is really no motivation. But this can also be established intellectually, and from direct experience. We see that all beings strive to be free from the things that torment them in one way or another, whether it is a bug hiding under a leaf during a storm, or a person popping pills in order to deal with stress, or just wiggling around in your chair to be more comfortable than you are now. So, we don't have to "believe" this. We can know this.
That might be where the difference is.
Profile Picture: "The Foaming Monk"
The Chinese characters are Fo (buddha) and Ming (bright). The image is of a student of Buddhism, who, imagining himself to be a monk, and not understanding the true meaning of the words takes the sound of the words literally. Likewise, People on web forums sometime seem to be foaming at the mouth. Original painting by P.Volker /used by permission.