If we do not properly execute our mission of life in self-realization, nature's punishment will render us inactive by putting us in the form of trees and hills
SB Canto 4
For human society, constantly thinking of how to earn money and apply it for sense gratification brings about the destruction of everyone's interests. When one becomes devoid of knowledge and devotional service, he enters into species of life like those of trees and stones.
Jñāna, or knowledge, means to understand one's constitutional position, and vijñāna refers to practical application of that knowledge in life. In the human form of life, one should come to the position of jñāna and vijñāna, but despite this great opportunity if one does not develop knowledge and practical application of knowledge through the help of a spiritual master and the śāstras—in other words, if one misuses this opportunity—then in the next life he is sure to be born in a species of nonmoving living entities. Nonmoving living entities include hills, mountains, trees, plants, etc. This stage of life is called puṇyatām or mukhyatām, namely, making all activities zero. Philosophers who support stopping all activities are called śūnyavādī. By nature's own way, our activities are to be gradually diverted to devotional service. But there are philosophers who, instead of purifying their activities, try to make everything zero, or void of all activities. This lack of activity is represented by the trees and the hills. This is a kind of punishment inflicted by the laws of nature. If we do not properly execute our mission of life in self-realization, nature's punishment will render us inactive by putting us in the form of trees and hills. Therefore activities directed toward sense gratification are condemned herein. One who is constantly thinking of activities to earn money and gratify the senses is following a path which is suicidal. Factually all human society is following this path. Some way or other, people are determined to earn money or get money by begging, borrowing or stealing and applying that for sense gratification. Such a civilization is the greatest obstacle in the path of self-realization.