One who is not a pure devotee of the Supreme Lord Krsna is not completely cleansed in the heart. But a perfectly cleansed person never quits the devotional service of the Lord. In discharging such devotional service, as ordered by Brahmaji to Narada in the preaching of Srimad-Bhagavatam, sometimes a representative of the Lord engaged in preaching work meets various so-called difficulties. This was exhibited by Lord Nityananda when He delivered the two fallen souls Jagai and Madhai, and similarly Lord Jesus Christ was crucified by the nonbelievers. But such difficulties are very gladly suffered by the devotees in preaching because in such activities, although apparently very severe, the devotees of the Lord feel transcendental pleasure because the Lord is satisfied. Prahlada Maharaja suffered greatly, but still he never forgot the lotus feet of the Lord. This is because a pure devotee of the Lord is so purified in his heart that he cannot leave the shelter of Lord Krsna in any circumstances. There is no self-interest in such service. The progress of culturing knowledge by the jnanis or the bodily gymnastics by the yogis are ultimately given up by the respective performers, but a devotee of the Lord cannot give up the service of the Lord, for he is ordered by his spiritual master. Pure devotees like Narada and Nityananda Prabhu take up the order of the spiritual master as the sustenance of life. They do not mind what becomes of the future of their lives. They take the matter very seriously as the order comes from the higher authority, from the representative of the Lord, or from the Lord Himself.