Śrīla Bhakti Rakṣak Śrīdhar Dev-Goswāmī Mahārāj summarises the necessity of preaching.
When we take the life of a preacher, we come face to face with comparative study of different religious conceptions. We are to meet this, strengthen our faith, and go on. Kīrtan means preaching, not only chanting the Name aloud in a high voice. The real meaning of kīrtan is preaching, to shake the atmosphere, shake the environment. Reactions will come for doing this, and we are to go and meet those reactions, develop our own internal position, and then march on. Kīrtan means this. Especially in Kali-yuga, where the environment is offensive even for the offensive, we have to be offensive: we have to attack, demolish, and go. We are to march consciously, not with only blind impressions. If we do that, we will have to suffer setbacks. But our march should be conscious, firm, and considerate. Otherwise, there is possibility of setbacks, to come down again. Our march must be thorough so that we do not have to retrace back.
Student: Guru Mahārāj, you say, “demolish and go”?
Śrīla Śrīdhar Mahārāj: Demolish the outside misconception and its representation. Clear it up. Ignorance is like mist, and we are to demolish it. We are to destroy nescience, ignorance, the misconceptions that we find around us in this world. We are to restore good health. Suppose one has gone to an unhealthy place like a hospital. There, so many germs come from different quarters to attack one’s body. The body has some resisting power, and one has to kill, demolish, those germs that come to attack one at the hospital and then withdraw. If we are weak, then those germs will come, attack, and kill us.
Reference
Spoken 23 December 1982.