Tamāla Kṛṣṇa: Sixteen; "My dear Arjuna, a man who does not follow this prescribed Vedic system of sacrifice certainly leads a life of sin. For a person delighting only in the senses lives in vain (BG 3.16)." Purport...
Prabhupāda: Yes, this is very important. Read purport. Go on.
Tamāla Kṛṣṇa: "The Mammonist philosophy of work very hard and enjoy sense gratification is condemned herewith by the Lord. For those who want to enjoy this material world, the above-mentioned cycle of sacrifices is absolutely necessary. One who does not follow such regulations is living a very risky life, being condemned more and more. By nature's law this human form of life is specifically meant for self-realization in either of the three ways—namely karma-yoga, jñāna-yoga or bhakti-yoga. There is no necessity of rigidly following the performances of the prescribed yajñas. Such transcendentalists are above vice and virtue, but those who are engaged in sense gratification require purification by the above-mentioned cycle of yajña performances. There are different kinds of activities. Those who are not Kṛṣṇa conscious are certainly engaged in sensory consciousness and therefore they need to execute pious work.