Śrīla Bhakti Sundar Govinda Dev-Goswāmī Mahārāj explains the substance of preaching Kṛṣṇa consciousness.
Actually, our practice and our preaching are the same thing: we preach what we practice. In our practice, we are not following so many rules and regulations, but we always follow the three directives of Śrīman Mahāprabhu: be humble, be tolerant, and give honour to others.
In this Age of Kali, what is actually necessary to rescue the conditioned souls from this illusory environment and take them to the transcendental service world is Hari-nām-saṅkīrtan, and our realisation from all the scriptures is that the three directives of Mahāprabhu give us super strength to practise this in our life.
In other ages, the residents of this material world, the conditioned souls, follow so many rules and regulations to be rescued, but in this Age of Kali, there is only one process to practise: chanting the Hare Kṛṣṇa mahāmantra. We must always chant the mahāmantra without offence, and when it is revealed in our heart, all inauspiciousness and disturbance—everything—will go away. That will be possible only by following the three directives: be humble, be tolerant, and give honour to others. These three qualities clean everything. Peace in this world will come only through them.
If we are humble, we are tolerant, and we give honour to everyone, then all the inauspiciousness will go away, everyone will be our friend, and peacefully we will be able to practise our spiritual life. Hari-nām-saṅkīrtan is the best in this life, and one who chants Hari-nām must be enriched with these three qualities and qualifications. This is the gift of Mahāprabhu.
Before, many Vedic practices and procedures gave people some relief, but they are hard to practise in this Age of Kali. It is not possible, actually, to purely follow the rules and regulation of the Vedas in this age.
Śrīmad Bhāgavatam, Śrīmad Bhagavad-gītā, and all the other scriptures have given Hari-nām-saṅkīrtan great importance. Everyone knows the mahāmantra. Of all mantras, the mahāmantra is the best. It is necessary, however, to chant it with some qualification, and that will come through the procedure given by Mahāprabhu Śrī Chaitanyadev. Mahāprabhu engaged in question and answer with Prakāśānanda Saraswatī and other great scholars, but lastly He rejected everything they proposed and said everything else is not necessary in this Age of Kali and cannot be done perfectly. Hari-nām-saṅkīrtan is the best for everyone, and Śrī Hari Himself is joyful to rescue any person who chants Hari-nām without offence.
We are making many preaching programmes and doing many things, but actually what we want to practise and advise others to practise is to chant the Hare Kṛṣṇa mahāmantra without offence and be happy. All the scriptures and all our Gurus said this, and we have dedicated our lives to this mantram. So, our devotees worldwide should always try to practise and preach this Kṛṣṇa consciousness. What shall I say more?
Reference
Spoken on 25 November 2007, in Soquel, California.