“There is undoubtedly trouble in executing penance. But the trouble accepted in executing bhakti-yoga is transcendental happiness from the very beginning, whereas the trouble of penance in other processes of self-realization (jnana-yoga, dhyana-yoga, etc.), without any Vaikuntha realization, ends in trouble only and nothing more. There is no profit in beating husks without grains. Similarly, there is no profit in executing troublesome penances other than bhakti-yoga for self-realization.” (Shrila Prabhupada, Shrimad Bhagavatam, 2.9.9 Purport)