There is the story of Viśvāmitra Muni, a great king, a kṣatriya, who renounced his kingdom and took to the yoga process in order to become more spiritually advanced. At that time the meditational yoga process was possible to execute. Viśvāmitra Muni meditated so intently that Indra, the King of heaven, noticed him and thought, “This man is trying to occupy my post.” The heavenly planets are also material, and there is competition—no businessman wants another businessman to exceed him. Fearing that Viśvāmitra Muni would actually depose him, Indra sent one heavenly society girl, named Menakā, to allure him sexually. Menakā was naturally very beautiful, and she was intent on disrupting the muni’s meditations. Indeed, he became aware of her feminine presence upon hearing the sound of her bangles, and he immediately looked up from his meditation, saw her, and became captivated by her beauty. As a result, the beautiful girl Śakuntalā was born by their conjugation. When Śakuntalā was born, Viśvāmitra lamented: “Oh, I was just trying to cultivate spiritual knowledge, and again I have been entrapped.” He was about to flee when Menakā brought his beautiful daughter before him and chastised him. Despite her pleading, Viśvāmitra resolved to leave anyway.
Thus there is every chance of failure on the yogic path; even a great sage like Viśvāmitra Muni can fall down due to material allurement. Although the muni fell for the time being, he again resolved to go on with the yoga process, and this should be our resolve. Kṛṣṇa informs us that such failures should not be cause for despair. There is the famous proverb that “failure is the pillar of success.” In the spiritual life especially, failure is not discouraging. Kṛṣṇa very clearly states that even if there is failure, there is no loss either in this world or in the next. One who takes to this auspicious line of spiritual culture is never completely vanquished.
Now what actually happens to the unsuccessful spiritualist?
Generally, according to the law of karma, if one enacts pious deeds, he is rewarded in the next life by birth into a very aristocratic family or into a very wealthy family, or he becomes a great scholar, or he is born very beautiful. In any case, those who sincerely begin spiritual life are guaranteed human birth in the next life—not only human birth, but birth into either a very pious or a very wealthy family. Thus one with such a good birth should understand that his fortune is due to his previous pious activities and to God’s grace. These facilities are given by the Lord, who is always willing to give us the means to attain Him.
Kṛṣṇa further indicates that of all good families to be born into—families of successful merchants or philosophers or meditators—the best is the family of yogīs. One who takes birth in a very rich family may be misled. It is normal for a man who is given great riches to try to enjoy those riches; thus rich men’s sons often become drunkards or prostitute hunters. Similarly, one who takes birth in a pious family or in a brahminical family often becomes very puffed up and proud, thinking, “I am a brāhmaṇa; I am a pious man.” There is chance of degradation in both rich and pious families, but one who takes birth in a family of devotees has a much better chance of cultivating again that spiritual life from which he has fallen.
Ref >> Srila Prabhupada Vani.