Altogether, faith, in its essence, is beyond the mental grasp of the human mind, and perhaps even of the soul.
It belongs to a realm of existence higher than our normal scope of cognition, where reasoning does not seem to be much use.
Similarly, in the physical life we may know a sensation of nameless fear without any reason; we may experience the inexplicable or visionary.
Yet faith is much higher even than these mystical experiences.
And even if the intellect is needed to make God comprehensible, it is not the mind that grasps God.
It therefore cannot be a simple matter to explain what faith is.
It may be appropriate first to relate to its contents.
The faith of Israel is primarily a belief in the one God who is more sublime than anything that has form or that can be conceived.
This faith rests also on providence, on personal Divine grace, on a particular relation to the individual person and situation.
This is the problematic faith which the research scholars cannot quite grasp. Indeed philosophies of all sorts, including those that take pains to prove the existence of God, have trouble with this problem of the relation between the world and the Divine, between personal providence and Divine essence.
–Rabbi Adin Steinsaltz