Central Sincerity refers to the fundamental reason or purpose for which the yoga is being undertaken. Is it to become a great yogi or a superman or to have powers and satisfy some kind of spiritual or other ambition? Even a purpose such as the idea of helping humanity is not sufficient to undertake the yoga. Even the lure for supraphysical experiences is a dangerous thing since the vital in man colluding with the mind can give form to any such wishes and one may never know whether one is having the authentic thing or simply imitations of the vital. People who take up yoga with the wish to have experiences such as visions and hearing voices or the idea of developing certain powers of which they can boast to others or with the idea of being a great sadhak, easily land themselves in the ‘valley of false glimmers’ or the ‘Intermediate Zone’ between material life and the true spiritual life. Once there the attachment for experience keeps them tied and trapped, often until they depart from their present life.
Central sincerity means that the yoga is not undertaken for any of these egoistic and selfish motives that ordinarily drive us but for the sake of the Divine, out of love for the Divine, to serve the Divine, to know the Divine, to be one with the Divine since such is the deepest urge of our nature. The only personal motive that can be said to be admissible for the yoga is growth and progress towards a diviner perfection of life. Though here too this is not something that is to be pursued as some kind of individual achievement such as experiencing some kind of personal bliss or peace but as part of the earthly realization, as the Will of God in us and in mankind. This central sincerity is important for the yoga since if it is pursued for any other side motives, especially personal egoistic motives, such as ambition, then there will be a fall from the yoga and a derailment of the process. Not that such things may not arise later. If these things are hidden in human nature, then the Force of yoga which is a Force of Truth will uncover them and they have to be dealt with with persistent rejection and surrender. But they should not the motive for undertaking the yoga.
This is as far as the aim of yoga is concerned. This does not mean that one cannot ask something for oneself when in distress or for the health and well-being of oneself and the family. Of course one can and the Divine Mother loves that it be so, a personal bond and a relation of complete trust between Her and Her children. In fact she Herself takes care of these things and many more, in fact She spreads a benevolent blanket of Her Peace and Light and Love and Grace upon all who have turned to Her with trust and surrounds them with Her ring and armour of Protection since now these souls have come directly under Her care. But these things cannot be the aim of the yoga or its central motive.
The aim of yoga, as the word itself implies is union with the Divine, through bhakti, love, surrender, aspiration, concentration or the simplest of all an utter self-giving to the Divine. In traditional yoga, this union is limited to a union of the Soul with the Divine. In the Integral yoga it extends to all other parts of our being, to the different strands of our complex nature, eventually in each and every movement and the details of our life. It is there that a detailed sincerity, an integral sincerity is needed in each part and movement that is called upon and aspires for the upliftment and union with its highest and most divine possibility.