There is a vast difference between a mental acknowledgement of a concept or idea, and the actual realisation that underlies that concept. It is not an infrequent occurrence for a spiritual aspirant to hold a mental belief that is, nevertheless, not a full realisation. Spiritual realisation is not an “idea” but a palpable experience that is what Sri Aurobindo calls a ‘knowledge by identity’. When Peace is mentioned, it is not some theoretical status but an actual overwhelming sense of peace that fills the being. Similarly, the descent of the Light is not a symbolic way to describe some kind of mental knowledge, but an experience of Light that fills the mind and, as it descends, the rest of the being in a very real and palpable way. The descent of the Force is also something experienced, not ‘thought about’.
The experience of these things may begin in a more receptive part of the being, the mind, or the heart. Other parts of the being may not yet be capable of receiving them, and thus, there is a dichotomy between the parts that are receptive and those that remain closed for the time being. The practice of detachment from the instrumental being, the ego-personality, the functionality of the mind, life and body allows the seeker to begin to shift the standpoint away from the ego, where it is involved and bound, to the divine standpoint, where it is free and is able to observe without any perturbation, the actual situation of the instrumental being.
Sri Aurobindo notes: “The thing is that it is unavoidable in the course of the sadhana that some parts of the being should be less open, less advanced, as yet less aware of the Peace and Force, less intimate to them than others. These parts have to be worked upon, and changed, but this can be done smoothly only if you are detached from them, able to regard them as not your very self, even though a part of the nature you have to change. Then when they appear with their defects, you will not be upset, not carried away by their movements, lost to the sense of the Peace and Force; you will be able to work on them (or rather let the Force work) as one would on a machine that has to be repaired or a work that has defects and has to be done better this time. If you identify yourself with these parts, then it is very troublesome. The work will still be done, the change made, but with delay, with bad upsettings, in a painful and not in a smooth way. That is why we always tell people to be calm and detached and look upon these things not as their true selves but as an outer part that has to be worked upon quietly until it is what it should be.”
Sri Aurobindo, Integral Yoga: Sri Aurobindo’s Teaching and Method of Practice, Chapter 10, Difficulties in Transforming the Nature, Detachment from Difficulties, pp. 277-278