A.C. Bhaktivedanta Swami Prabhupada, Picture Quotes

One should not be idle but should be very enthusiastic about executing the regulative principles. Neglect of the regulative principles will destroy devotional service. In this Krishna consciousness movement there are four basic regulative principles, forbidding illicit sex, meat-eating, gambling and intoxication. A devotee must be very enthusiastic about following these principles. If he becomes slack in following any of them, his progress will certainly be checked. — The Nectar of instruction, Text 03.
A.C. Bhaktivedanta Swami Prabhupada, Picture Quotes

Scientist display their intellectual energy & deny the existence of Supreme Energy…. but devotees worship Krishna as the greatest Scientist.
A.C. Bhaktivedanta Swami Prabhupada, Picture Quotes

Taking to Krishna consciousness and bringing fallen souls to Krishna consciousness is victory for Lord Krishna.
Srimad Bhagavatam 6.16.40
A.C. Bhaktivedanta Swami Prabhupada, Picture Quotes

On this gross planet earth, there are airplanes run by machine, but on other planets the airplanes are run not by machine but by mantric hymns.