One must execute devotional service under the guidance of a devotee or directly under the guidance of the Supreme Personality of Godhead. It is not possible, however, to train oneself without guidance from the spiritual master.
By the slow process of devotional service, under the guidance of the bona fide spiritual master, one can attain the highest stage.
One must seek the association of persons who are Krishna Conscious and who engage in devotional service. Without such association one cannot make advancement.
In the association of pure devotees, discussion of the pastimes and activities of the Supreme Personality of Godhead is very pleasing and satisfying to the ear and the heart. By cultivating such knowledge one gradually becomes advanced on the path of liberation and thereafter he is freed and his attraction becomes fixed. Then real devotion and devotional service begin.
There are many societies and associations of pure devotees and if someone with just a little faith begins to associate with such societies, his advancement to pure devotional service is rapid.
Devotional service is not our property, It is a privilege given to us by Guru and Krishna.