Truth is subjectivity. Rationality and knowledge are based on the premise that truth is objective, impersonal, a relationship between a belief and the world. But the truth about human existence is not something about which we are simply intellectually curious but is rather something about which we care deeply. Our existence and salvation are meaningful not because they correspond to some objective fact but because our interest in them is unconditioned and passionate, without any inner reservations or doubt. Only a leap of faith can surmount the gap.
Moral knowledge is general, faith in salvation is particular.
The leap of faith is not irrational as much as beyond rationality.