SB 11.21.22
visayabhinivesena
natmanam veda naparam
vrksa jivikaya jivan
vyartham bhastreva yah svasan
Translation:
Because of absorption in sense gratification, one cannot recognize himself or others. Living uselessly in ignorance like a tree, one is merely breathing just like a bellows.
Purport:
Just as trees, having no means of defending themselves, are always being cut down, similarly, the conditioned souls are constantly being cut down by the cruel laws of nature, which impose innumerable miseries culminating in sudden death. Although foolish people think they are helping themselves and others, they actually do not know their own identity, nor the identities of their so-called friends and relatives. Absorbed in gratifying the senses of the external body, they spend their lives uselessly, without spiritual profit. This useless lifestyle can be transformed into a perfect life simply by chanting the holy names of God in Krsna consciousness, as recommended by Sri Caitanya Mahaprabhu.