SB 11.14.21

bhaktyāham ekayā grāhyaḥ
 śraddhayātmā priyaḥ satām
bhaktiḥ punāti man-niṣṭhā
 śva-pākān api sambhavāt
Word for word: 
bhaktyā — by devotional service; aham — I; ekayā — unalloyed; grāhyaḥ — am to be obtained; śraddhayā — by faith; ātmā — the Supreme Personality of Godhead; priyaḥ — the object of love; satām — of the devotees; bhaktiḥ — pure devotional service; punāti — purifies; mat-niṣṭhā — fixing Me as the only goal; śva-pākān — dog-eaters; api — even; sambhavāt — from the contamination of low birth.
Translation: 
Only by practicing unalloyed devotional service with full faith in Me can one obtain Me, the Supreme Personality of Godhead. I am naturally dear to My devotees, who take Me as the only goal of their loving service. By engaging in such pure devotional service, even the dog-eaters can purify themselves from the contamination of their low birth.
Purport: 

Sambhavāt indicates jāti-doṣāt, or the pollution of low birth. Jāti-doṣa does not refer to mundane social, economic or professional status, but rather to one’s degree of spiritual enlightenment. All around the world, many people are born into rich and powerful families, but they often acquire abominable habits that are part of their so-called family tradition. However, even unfortunate persons who are taught from birth to engage in sinful activities can at once be purified by the potency of pure devotional service. Such service must have Lord Kṛṣṇa as the only goal (man-niṣṭhā), must be rendered with full faith (śraddhayā), and must be unalloyed, or without any selfish motivation (ekayā).