Evam pravartitam cakram nanuvartayatiha yah
aghayur indriyaramo mogham partha sa jivati
(Text 16, Ch 3, Karma Yoga)
Meaning : My dear Arjuna (devotee), one who does not follow in human life the cycle of sacrifice thus established by the Vedas certainly leads a life full of sin. Living only for the satisfaction of the senses, such a person lives in vain.
***By nature’s law, this human form of life is specifically meant for Self-Realization, in either of three ways-namely Karma-yoga, jnana-yoga or bhakti-yoga. There is no necessity of rigidly following the performance of the prescribed yajnas for the transcendentalists who are above vice and virtue; but those who are engaged in sense gratification require purification by the above mentioned cycle of yajna performances.