If one always chants the holy name of Kṛṣṇa, gradually one is freed from all reactions of sinful life, provided he chants offenselessly and does not commit moresinful activities on the strength of chanting the Hare Kṛṣṇa mantra. In this way one is purified, and his devotional service causes the arousal of his dormant love of God. If one simply chants the Hare Kṛṣṇa mantra and does not commit sinful activities and offenses, one's life is purified, and thus one comes to the fifth stage of perfection, or engagement in the loving service of the Lord (premā pum-artho mahān).
(Sri Caitanya Caritamrta---1:8:26---purport).

Due to our association with the modes of material nature, we get different types of bodies, good and bad. One cannot be liberated from the cycle of birth and death, known as transmigration of the soul, unless one is completely freed from all sinful activities. The best process, therefore, is to take to Kṛṣṇa consciousness. One cannot take to Kṛṣṇa consciousness without being freed from all sinful activities. Naturally one who is very serious about Kṛṣṇa consciousness is freed from all sinful activity. Consequently a devotee is never inclined to commit sins. If one is pressured by the law or obligations to give up sinful activity, one cannot do so. However, if one takes to Kṛṣṇa consciousness, he can very easily give up all sinful activity.
(Sri Caitanya Caritamrta---2:22:142---purport).

Foolish people do not know that every individual soul is responsible for his own actions and reactions in life. As long as a living entity in the form of a child or boy is innocent, it is the duty of the father and mother to lead him into a proper understanding of the values of life. When a child is grown, it should be left up to him to execute the duties of life properly. The parent, after his death, cannot help his child. A father may leave some estate for his children's immediate help, but he should not be overly absorbed in thoughts of how his family will survive after his death. This is the disease of the conditioned soul. Not only does he commit sinful activities for his own sense gratification, but he accumulates great wealth to leave behind so that his children may also gorgeously arrange for sense gratification.
(Srimad Bhagavatam---4:28:22---purport).

This is the law of the Supreme Personality of Godhead. The conditioned souls, who have come to this material world for sense gratification, are allowed to enjoy their senses under certain regulative principles. If they violate these regulations, they are judged and punished by Yamarāja. He brings them to the hellish planets and properly chastises them to bring them back to Kṛṣṇa consciousness. By the influence of māyā, however, the conditioned souls remain infatuated with the mode of ignorance. Thus in spite of repeated punishment by Yamarāja, they do not come to their senses, but continue to live within the material condition, committing sinful activities again and again.
(Srimad Bhagavatam---5:26:6---purport).

Nondevotees must undergo material hardships because they are prone to commit sinful fruitive activities. The desire to commit sinful actions continues in their hearts due to ignorance. These sinful actions are divided into three categories—pātaka, mahā-pātaka and atipātaka—and also into two divisions; prārabdha and aprārabdha. Prārabdha refers tosinful reactions from which one is suffering at the present, and aprārabdha refers to sources of potential suffering. When the seeds (bīja) of sinful reactions have not yet fructified, the reactions are called aprārabdha. These seeds of sinful action are unseen, but they are unlimited, and no one can trace when they were first planted. Because of prārabdha, sinful reactions that have already fructified, one is seen to have taken birth in a low family or to be suffering from other miseries.
(Srimad Bhagavatam---6:1:15---purport).

The sinful actions of one who has surrendered unto Kṛṣṇa are compared to a snake with its poison fangs removed (protkhāta-daṁṣṭrāyate). Such a snake is no longer to be feared. Of course, one should not commit sinful activities on the strength of having surrendered to Kṛṣṇa. However, even if one who has surrendered to Kṛṣṇa happens to do something sinful because of his former habits, such sinful actions no longer have a destructive effect. Therefore one should adhere to the lotus feet of Kṛṣṇa very tightly and serve Him under the direction of the spiritual master. Thus in all conditions one will be akuto-bhaya, free from fear.
(Srimad Bhagavatam---6:1:19---purport).

One may atone for sinful life and vanquish all sinful reactions by chanting the holy name, although this is not called atonement. Ordinary atonement may temporarily protect a sinful person, but it does not completely cleanse his heart of the deep-rooted desire to commit sinful acts. Therefore atonement is not as powerful as the chanting of the holy name of the Lord. In the śāstras it is said that if a person only once chants the holy name and completely surrenders unto the lotus feet of the Lord, the Lord immediately considers him His ward and is always inclined to give him protection.
(Srimad Bhagavatam---6:2:49---purport).