Brahma Gyan is the highest knowledge. Once this knowledge is gained and imbibed, no other knowledge remains to be gained. Brahma Gyan is the king of all knowledge, it is the king of all secret knowledge as well and is utterly holy, utterly beneficial, utterly righteous and gives results as soon as it is practiced properly. It is also easy to practice and is eternal and unchanging. Brahma Gyana is the only way to reach the state of enlightenment and there is no other way to reach that exalted state. Brahma Gyana is not a work that has to be done, it is only to be known and believed and once that happens then the devotee reaches the state of enlightenment. The main fruit of Brahma Gyan is the crossing of the soul from the state of creation to beyond creation-Parabrahma. The state of Parabrahma is one which is beyond all duality-beyond birth and death; distortions and separations; eternal and indestructible; free of sin and completely holy.
The fruit of all fire sacrifices is to reach the state of heaven but then return after the fruit is over but the fruit of Brahma Gyana is to reach beyond creation and never return to the cycle of birth and death.
Those devotees who want to escape the attraction of indulgences in sensory pleasures, and who constantly strive to do that, those people do not take long to find this eternal state. They experience the manifestation of the Lord in this body and in this life itself. It is certain that those who have resolved to find the Lord and have renounced actions that lead to sensory indulgences; they find realization in this life itself. The Mahabharata in page number 1256 mentions that whether man or woman, the one who realizes Brahma Gyana, he or she is not reborn. If a person finds Brahma Gyana and leaves desire, then in this body itself-without dying- he will find realization. In Shrimad Bhagwat Mahapuraan 11;29:18, the Lord tells Uddhav that when Brahma Gyana is studied then in only a few days everything and everyone starts looking like Brahma to the devotee. When this vision is gained then all doubt; fear; separation disappear on their own accord and one sees the vision of the lord in all directions and in everything.
In Shrimad Bhagwat Mahapuraan 11:29:26 the Lord says that the person who explains Brahma Gyana to the seekers of the truth, He would be so pleased with that person that to that person He would grant His own being.