Nature of a Devotee – A Devotee never claims that he is a great devotee
Devotee do not want liberation, they only want to serve. Service here or service there doesn't matter. 'Let me always serve you', that is the mood of a devotee.
The symptom of a Vaishnava is trinad api sunicena taror api sahisnuna, that's the perfect definition of a Vaishnava. Another consideration is that a Vaishnava is a surrendered soul to Krishna.
By practice or by becoming sinless we will not become a pure devotee but by surrendering to Krishna we will become a pure devotee.
Devotees apparently go through some difficulities at a time but those difficulties do not affect them by any means because they are always protected by Krishna's merciful embrace.
When we associate with devotees we slowly-slowly get to know about their great qualities and thus we give our envious nature.