Bhagavad Gita: Chapter 9, Verse 30

BG 9.30: Even if the vilest sinners worship Me with exclusive devotion, they are to be considered righteous because they have made the proper resolve.

Devotion to the Supreme Lord is so potent that it can reform even the most fallen.  In the scriptures, the classical examples of this are Ajamil and Valmiki, whose stories are commonly sung in all Indian languages.  Valmiki’s impious deeds were so overbearing that he was unable even to enunciate “Ra..ma,” the two syllables in Lord Ram’s name.  His sins were preventing him from taking the divine Name.  So, his Guru thought of a way of engaging him in devotion by making him chant the reverse, “Ma Ra,” with the intention that repetition of “Mara Mara Mara Mara…” will automatically create the sound of “Rama Rama Rama…”  As a result, even such a fallen soul as Valmiki was reformed by the process of ananya bhakti (exclusive devotion) and transformed into a legendary saint. 

ulaṭā nāmu japata jagu jānā, bālmīki bhae brahma samānā.  (Ramayan)

“The whole world is testimony to the fact that Valmiki attained sainthood by chanting the syllables of God’s Name in the reverse order.”  Therefore, sinners are not condemned to eternal damnation.  On the strength of the transforming power of bhakti, Shree Krishna declares that even if the vilest sinners begin worshipping God exclusively, they should no longer be designated as sinners.  They have made a pure resolve and should thus be considered righteous due to their sublime spiritual intention.