The scientific technique of yogasadhana can only impart nirvana that is going beyond the birth-death cycle.
All of us execute actions good or bad which inevitably has a consequence. Good actions harbour good results, bad action bad. This is the principle of cause and effect or yogically the law of karma. But a yogi practising Pranakarma goes beyond this law of karma. This is an exalted state of a yogi because only fervent austere endeavours enable him to attain complete emancipation (moksha).
No matter how much one is pious or diligent in regular prayers or performs good actions with his kinetic mind but a yogi does not pray in the stipulated sense. His prayer is Pranakarma (inherent-intrinsic action) through which he causes a cessation of the external breathing motion hence all the dynamism which is superficial and ultimately merges in the Absolute still state from which there is no return.
Just as thirst is quenched when one drinks a glass of water, for this the person has to make effort to obtain it, similarly attainment of salvation or moksha is not easy. By simply crying for it repeating the word ‘moksha’ salvation is impossible.
Only through the yogic process of stilling the kineticism of the body and mind and ultimately losing all material attachment uniting with the Absolute Supreme Brahma, salvation is possible.
Thus the endeavour for quenching spiritual thirst is imperative.