As long as someone remains a Yavana, we remain indifferent to him.   

However, when someone who was formerly a Yavana becomes a Vaisnava by the influence of nitya-sukrti, we no longer consider him a Yavana.   

This is noticeably clear in the following statement from the Padma Purana: 

 “If one considers a devotee of Bhagavan to be a member of the lowest of the four castes (sudra), a member of an aboriginal tribe of hunters, or an outcaste dog-eater, merely because the devotee has taken birth in such families, one is assuredly destined for hell.” 

The Itihasa-samuccaya also says: 

 “A brahmana who has studied the four Vedas, but has no bhakti, is not dear to Me, whereas My bhakta is very dear to Me, even if he has taken birth in a family of dog-eaters.  Such a bhakta is fit to receive charity, and whatever he offers should be accepted.  Indeed, he is as worshipable as I am.”