The so-called progressive modern civilization has produced reprobate human beings, whose sins have been accumulating over many lifetimes. Yet if they surrender to Lord Kṛṣṇa, even they will have all their sins eradicated forever. The process of devotional service and remembrance of Lord Kṛṣṇa will gradually dissipate unwanted, base desires from within their hearts. And those hearts, which previously sheltered immoral yearnings will become fully cleansed and auspicious.
The sinful and the destitute can understand their mistakes and misfortune only by Lord Kṛṣṇa's mercy. Once they begin to repent for their sins and surrender to the Lord, they are saved; they become purified and start manifesting saintly characteristics. And if even after a person takes to the devotional process some vestige of immorality remains in his character, that also will soon be eradicated by the Lord's grace. The single-minded devotee who never offends the Supreme Lord or His devotees is to be considered a saintly soul. Even if it seems that such a saint is not yet rid of all sinful propensities, he will never be destroyed, as are the yogīs and karmīs in a similar situation. This the Supreme Lord Himself has declared.
The Śrīmad-Bhāgavatam's account of the deliverance of Ajāmila conclusively proves this fact. Once undeviating faith in devotional service to Lord Kṛṣṇa penetrates a person's heart, the process of purification is firmly underway, even though his external activities may show residues of sin. Lord Kṛṣṇa has boldly broadcast in the Bhagavad-gītā (9.31) His promise that His surrendered devotees can never be vanquished: kaunteya pratijānīhi na me bhaktaḥ praṇaśyati. That Lord Kṛṣṇa will always protect His devotees is proved in this verse, especially since the Lord, instead of declaring the promise Himself, asks the valiant prince Arjuna to do so on His behalf. The Lord may break His own promise, but because He is favorable to His devotees, He will always try to uphold their promises. By breaking His own promise and keeping Bhīṣmadeva's on the battlefield of Kurukṣetra, the Lord has proved beyond a doubt that He favors His surrendered devotees .
A brāhmaṇa or someone of noble birth endowed with beauty, wealth, and learning may fallaciously conclude that elimination of degraded habits still visible in a devotee can occur only in the case of a brāhmaṇa like Ajāmila. Ajāmila was a brāhmaṇa by birth, but on account of sinful activities caused by bad reactions from his past life, he began performing abominable activities. At the end of his life, however, his remembrance of the Supreme Lord absolved him of all sins. But deliverance is possible for everyone, not just those of high birth. Even the lowest people, who are naturally given to base activities, can reach the spiritual abode of Lord Kṛṣṇa if they simply surrender at His lotus feet.