"Ninety-nine point nine percent people, they want to become happy within this material world. Therefore they are poor, very, very poor. And the mahatmas, they give the knowledge that 'This is not life. This is a temporary platform.' Asasvatam, duhkhalayam asasvatam [Bg. 8.15]. This is confidential knowledge. You are trying to be happy... Suppose Brahma. He lives for many millions of years. Still, it is duhkhalayam asasvatam [Bg. 8.15]. That life is also temporary. What is millions of years' duration of life in comparison to the eternal life? So beginning from Brahma down to the small ant, whoever is within this material world, it is to be understood their understanding is very poor. And the mahatma, being kind upon these poor souls, they deliver the same knowledge as Krishna gives. Sarva-dharman parityajya mam ekam saranam... [Bg. 18.66]. This is guru's business."
(Srila Prabhupada lecture, Vrndavana, August 11, 1974)