Caitanya Mahaprabhu's movement means to become compassionate to the poor people. Poor people means that those who are poor in spiritual understanding, Krsna consciousness. They are poor. They are thinking they are very big men, but they are the poorest, because they are losing the chance of understanding Krsna in this human form of life. They are thinking this motorcar or this big, high palatial buildings and bank balance, big business profits — that is the aim of achievement. No. That is not the aim of achievement. The aim of achievement it to athato brahma-jijnasa — to understand Brahman. That is the aim of life. But they are not interested in that aim of achievement; therefore very, very poor. And Caitanya Mahaprabhu's business, or mission, is to reclaim these poor human beings — those who are not interested in spiritual understanding.

From Srila Prabhupada's lecture on Bhagavad-gita 4.1 — February 7, 1974, Vrndavana