The Supreme Personality of Godhead advised the two doorkeepers, Jaya and Vijaya, that by dint of bhakti-yoga in anger they would be delivered from the curses of the brāhmaṇas. Śrīla Madhva Muni remarks in this connection that by practicing bhakti-yoga one can become free from all sinful reactions. Even a brahma-śāpa, or curse by a brāhmaṇa, which cannot be overcome by any other means, can be overcome by bhakti-yoga.
One can practice bhakti-yoga in many rasas. There are twelve rasas, five primary and seven secondary. The five primary rasas constitute direct bhakti-yoga, but although the seven secondary rasas are indirect, they are also counted within bhakti-yoga if they are used in the service of the Lord. In other words, bhakti-yoga is all-inclusive. If one somehow or other becomes attached to the Supreme Personality of Godhead, he becomes engaged in bhakti-yoga, as described in Śrīmad-Bhāgavatam (SB 10.29.15): kāmaṁ krodhaṁ bhayam. The gopīs were attracted to Kṛṣṇa by bhakti-yoga in a relationship of lusty desire (kāma). Similarly, Kaṁsa was attached to bhakti-yoga by dint of fear of his death. Thus bhakti-yoga is so powerful that even becoming an enemy of the Lord and always thinking of Him can deliver one very quickly. It is said, viṣṇu-bhaktaḥ smṛto daiva āsuras tad-vipanyayaḥ: "Devotees of Lord Viṣṇu are called demigods, whereas nondevotees are called asuras." But bhakti-yoga is so powerful that both demigods and asuras can derive its benefits if they always think of the Personality of Godhead. The basic principle of bhakti-yoga is to think of the Supreme Lord always. The Lord says in Bhagavad-gītā (BG 18.65), man-manā bhava mad-bhaktaḥ: "Always think of Me." It doesn't matter which way one thinks; the very thought of the Personality of Godhead is the basic principle of bhakti-yoga.
In the material planets there are different grades of sinful activities, of which disrespecting a brāhmaṇa or a Vaiṣṇava is the most sinful. Here it is clearly stated that one can overcome even that grave sin simply by thinking of Viṣṇu, not even favorably but in anger. Thus even if those who are not devotees always think of Viṣṇu, they become free from all sinful activities. Kṛṣṇa consciousness is the highest form of thought. Lord Viṣṇu is thought of in this age by chanting Hare Kṛṣṇa, Hare Kṛṣṇa, Kṛṣṇa Kṛṣṇa, Hare Hare/ Hare Rāma, Hare Rāma, Rāma Rāma, Hare Hare. From the statements of the Bhāgavatam it appears that if one thinks of Kṛṣṇa, even as an enemy, that particular qualification—thinking of Viṣṇu, or Kṛṣṇa—cleanses one of all sins.