In ‘Fear and Trembling’, Kierkegaard sets Passion in opposition to Reflection, which was the dominant mood in Kierkegaard’s day, and remains the dominant mood of the 19th, 20th, and even 21st centuries..
Whilst reflection is the disinterested intellectualization of matters, by contrast passion throws itself in wholeheartedly. In particular, Kierkegaard stresses the importance of passion to faith. Without passion’s ‘leap’, there is no faith. Faith has been betrayed by demanding it make sense of that in life which simply does not, and will never, ‘add up.’ Faith, as leap of passion, accepts and enters the realm of the ‘Absurd.’ This means faith is more courageous, more willing to take a risk and venture something in the living of it, than reflection. Reflection says something must be comprehended before it can be lived; faith says the opposite= that something must be lived before it can be understood.
In fact, one cannot make the Absurd fully or even partially comprehensible; but one can wrestle with it, and come through it experientially. Thought cannot dent the Absurd, but experience enters and passes through its gateless gate. That is the paradox.
The fruits of reflection can be learned from another, but one must experience passion oneself in order to learn from it.
The willingness to go on in experience — remaining open, under going and going through whatever befalls — is another description of ‘passion.’ Where reflection stops= this is where passion goes on, leaping into the unknown, leaping into the pained, leaping into the non guaranteed.
Kierkegaard also usefully pointed out that existential distinctions are not so much difficult to draw as hard to live.
As a commentator has pointed out, ‘we humans take hope in the irrational.’