Answer: Indian scriptural instruction: `Pravritir esa bhutanam nivrittis tu maha-phala' --- Path of worldly mindedness and the path of renunciation. Conditioned souls are generally eligible for `path of worldly mindedness'. Persons eligible for `path of renunciation' are very rare.
When conditioned souls become averse to worship of Supreme Lord they are enveloped by external material potency consisting of three primal qualities- Sattvah, Rajah and Tamah. Living beings are created by Rajah guna, they are sustained for some time by Sattva guna and they are destroyed by Tamah guna. Conditioned souls have become victims of birth, death and threefold afflictions. The real self `Atma' originates from marginal potency or according to Gita, originates from Para-shakti. Atma is Anu-saccidananda --- minute existence, knowledge and bliss entity. As Atma is the outcome of marginal potency (a demarcating line between Internal potency and External potency), they can go either side. When they become averse to God by misusing their relative independence, they are enveloped by external or illusory energy. After 8 millions of births of different species, they become human beings. God gives them discriminating power between eternal and non-eternal. They can accept Eternal Reality Supreme Lord and worship Him. Previously in ancient times, Varnashram Dharma was prescribed according to quality and action- four Vranas and four Ashrams were introduced. Four Vranas --- Brahmin, Kshatriya, Vaishya and Sudra. Four Ashrams- Brahmachari, Grihastha, Vanaprastha and Sannyasa. This subject is very elaborate and scientific. It is not possible to have elaborate discussion of it through letter. Many scriptural evidences are to be referred to. There is a gradual procedure to attain the highest spiritual stage.
Due to foreign invasions, Indian scientific process of social enhancement was disturbed. The social systems are different in foreign countries. So it is irrelevant to go into it in detail. They will not find interest in it. It will be boring for them. Varnashram Dharma is only in vogue in India. In Kaliyuga, Varnashram dharma has become deteriorated due to foreign influence.
Incompetent persons, finding difficulty after marriage to lead household life and to maintain family members, give up family life. By that they commit sin. Acceptance of Sannyasa for them is prohibited. There may be some exceptional cases --- by providence, some fortunate persons may come in contact with bona fide sadhus and get chance of getting the temperament of worshipping God and leading restricted lives.
In Srimad Bhagavat, third canto, Kapil Bhagavan in His instruction to mother Devahuti said about the original and concomitant qualities of a bona fide pure devotee --- sadhu. He mentioned in His instruction, one of the original qualifications of sadhu should be- `Mat-krite tyakta-karmanas tyakta-svajana-bandhavah' --- abandoning of Varnashram dharma and relinquishing of bodily relations and friends are allowed if it is for the propitiation of Supreme Lord. In case there is any other ulterior motive, to fulfil material desires, then abandoning of Varnashram duties and relations will be considered as sinful act.
For getting actual knowledge of it, one should go through the topic of conversation between Sri Chaitanya Mahaprabhu and Sri Rai Ramananda in Kovur, South India, narrated by Srila Kaviraj Goswami in Sri Chaitanya Charitamrita.