Abruptly, if we take to sannyasa order, then… We have seen many persons abruptly taking or without understanding the self-realization process. He fails. He again comes back to the materialistic way of life in a different form. Suppose he begins in philanthropic work, some hospitalizing or opening educational institution. That is nice, but these things are being done by the government and many philanthropic persons. That is not the duty of a sannyasi. A sannyasi, a renounced order of life, his main business is to spread Krsna consciousness, or God consciousness. That is his real business. But if one has not the taste what is Krsna consciousness, simply accept sannyasa, then he will do all this nonsense work.

Sannyasa means to give up all material contaminated activities for the sake of the Supreme Lord.

From Srila Prabhupada's lecture on Bhagavad-gita 3.1-5 — Los Angeles, December 20, 1968