Faith is a quality, like courage or generosity. It is not the same as belief which is a matter of conviction about certain matters. Belief can be a support to faith, though belief is always vulnerable since it depends upon conditions in a way that faith does not need to. Faith that is dependent upon belief is not entirely secure. In the West we have mostly cultivated this kind of dependent faith, but real faith goes beyond it.
If we think of the analogy with courage, say, if you are in a battle and you firmly believe that you are going to survive this may assist you in acting with courage in the fighting, but something may happen that shakes your belief. If your courage is dependent upon your belief then at that point it will fail; whereas, it is possible to have courage no matter what, and this is a deeper and more solid form of courage. The same is true with faith.
Again, if you believe that you will always receive as much as you give, then this belief will support you in being a generous person, but again this belief may be shaken and if your generosity is dependent upon the belief then it will fail at that point. However it is possible to be generous without concern for whether one will be benefitted or not. Such unconditional generosity is deeper and more genuine.
Similarly, if one believes that as a person of faith one is going to be reborn in heaven or in the Pure Land of Amitabha Buddha, such a belief may sustain one's faith, but, again, there is a vulnerability here created by the condition. A person of unconditional faith will have faith no matter what happens, nor where nor whether he or she is reborn. A true bodhisattva is willing to be reborn wherever there is a need.
The conditionality can work the other way around. If one has unconditional faith, that faith can be a condition for the arising of beliefs. One may, with St Julian of Norwich, believe that "Though sin is behovable, all shall be well." Or, in more Buddhistic terms, that even though the cosmos be consumed in fire, one will pass through it in order to be with the Buddha. One might not even really know what this means, but it is an expression of the unconditionality of one's faith.
Faith that depends upon a belief condition can lead to conflict because one feels a need to defend the condition, but beliefs that depend upon an unconditional faith do not give rise to conflict because they are all-encompassing. In this second case, if somebody else has a different form of words, it matters not. One recognises the substance and does not get hung up on the form. We have done ourselves a disservice by making beliefs into a criterion of faith, which is putting the cart before the horse.
The deepest faith is unconditional and it is indistinguishable from wisdom. It penetrates the iron wall and is an unimpeded light. It is the radiance of all the Buddhas.