People think Self-knowledge or Brahma Gnana or Atma Gnana is very difficult to achieve or understand. Self-knowledge or Brahma Gnana or Atma Gnana which has to be acquired carefully and gradually, through deeper self-search.
In the past, spirituality was treated not as a separate subject but as a part of religion, but it is not so. Religion is based on the form and spirituality is based on formless. Therefore, spirituality is nothing to with religion. Spirituality is a rational inquiry regarding all that is known to exist. Every one, each to the extent to which one's reasoning power admits, is by nature free to exercise this faculty, at whatever stage one may be. One is able to devote himself exclusively to a pursuit of the highest Truth, by means of reason.
In the ancient time, religious, Yogic or mystic disciplines, which were not an end in itself, considered to be a means for self-realization. But such discipline is almost impossible task for the modern man to adopt. Day by day modern man is becoming aware of the fact that, religion and yoga are nothing to do with the ultimate truth or Brahman.
The modern mindset is pre-eminently scientific owing to the great progress that science has made. And the best method of freeing the one from his inaccurate ways of thinking is to imbue him as fully as possible with the scientific spirit. It is therefore only one who possesses a clear knowledge of its methods and results i.e., who is able to make reason the highest means of inquiry that would be fit for Self-knowledge or Brahma Gnana or Atma Gnana.
Vedanta itself admits its highest Truth that is Atman or Brahman cannot be reached by any path other than that of reason and unless the reason is sharper than the ‘Edge of a razor'. Reason on the true base is the highest means of attaining Self- knowledge or Brahma Gnana or Atma Gnana.
Religion,theology, mystic practice and yoga are not the means to acquire non-dual wisdom. Absence of reason is absence of wisdom.
Either the formless soul or self-witnesses the waking or dream or it does not see it at all. It means the seer is apart from the waking or dream. When the formless witness witnesses nothing, one calls it deep sleep. Thus one has to become mentally aware of the existence of the formless witness of the three states, which is the formless soul, which is in the form of consciousness, to realize the fact that, there is no division. The whole experience of diversity (waking or dream) is a mere mirage created out of single stuff, which is consciousness.