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This is practical and authorized, and one can also test himself to see how he is advancing simply by chanting. This Krishna consciousness movement is not something new, something that we have introduced or manufactured. It is authorized on the Vedic principles, authorized by acharyas like Chaitanya Mahaprabhu and others. And the method is very simple; there is no loss. We are not charging anything, we are not asking for fees and giving the people some secret mantra and promising them that within six months they will become God. No. This is open for everyone—children, women, girls, boys, old people—everyone can chant and see the results!

Ref: Krishna Consciousness— The Yoga for the Modern Age authored by Srila Prabhupada (Founder - Acharya, ISKCON)