Srimad-Bhagavatam: Canto 6 - Chapter 1 - Verse 4
प्रायो मुमुक्षवस्तेषां केचनैव द्विजोत्तम ।मुमुक्षूणां सहस्रेषु कश्चिन्मुच्येत सिध्यति ॥ ४ ॥
prāyo mumukṣavas teṣāṁkecanaiva dvijottamamumukṣūṇāṁ sahasreṣukaścin mucyeta sidhyati
O best of the brāhmaṇas, Śukadeva Gosvāmī, out of many persons who follow religious principles, only a few desire liberation from the material world. Among many thousands who desire liberation, one may actually achieve liberation, giving up material attachment to society, friendship, love, country, home, wife and children. And among many thousands of such liberated persons, one who can understand the true meaning of liberation is very rare.
There are four classes of men, namely karmīs, jñānīs, yogīs and bhaktas. This statement pertains especially to karmīs and jñānīs. A karmī tries to he happy within this material world by changing from one body to another. His objective is bodily comfort, either in this planet or in another. When such a person becomes a jñānī, however, be aspires for liberation from material bondage. Among many such persons who aspire for liberation, one may actually be liberated during his life. Such a person gives up his attachment for society, friendship, love, country, family, wife and children. Among many such persons, who are in the vānaprastha stage, one may understand the value of becoming a sannyāsī, completely accepting the renounced order of life.