What is ordinarily called a spiritual experience is the intense need for something other than the life one lives, and most often this awakens after difficulties or disappointments or pain or sorrow, all these things which bring unhappiness and at the same time arouse the aspiration for a better state. It is this that is generally at the root of spiritual experiences: it is something negative.
The positive need to know the Divine and unite with Him usually comes much later. I say usually; there are exceptions, but usually it is at first a flight from the miseries of life which pushes you towards the spiritual life. Very few people, if they were in a state of perfect inner and outer harmony and nothing unpleasant or painful happened to them, very few people would think of the Divine; they would not concern themselves with Him, they would be content with the half-measures of ordinary things and would not seek for an absolute. That is what Sri Aurobindo means.
But, when one has found this spiritual life, one realises that it is everywhere behind all appearances, as well as directly, without appearances. Behind appearances it also exists; this is what he says: we must find and reconcile these oppositions. There is a place or a state of consciousness in which they are reconciled.
Ref : Questions and Answers 1956