## Chapter XIII Preachers Must Know the Philosophy of Kṛṣṇa Consciousness
### 1. All devotees, especially preachers, must know the philosophy of Kṛṣṇa consciousness:
**The blessed messengers of Lord Viṣṇu, the Viṣṇudūtas, said: If you are actually servants of Yamarāja, you must explain to us the meaning of religious principles and the symptoms of irreligion.**
This inquiry by the Viṣṇudūtas to the Yamadūtas is most important. A servant must know the instructions of his master. The servants of Yamarāja claimed to be carrying out his orders, and therefore the Viṣṇudūtas very intelligently asked them to explain the symptoms of religious and irreligious principles.... The question posed by the Viṣṇudūtas was very suitable. One who represents someone else must fully know that person's mission. The devotees in the Kṛṣṇa consciousness movement must therefore be fully aware of the mission of Kṛṣṇa and Lord Caitanya; otherwise they will be considered foolish. All devotees, especially preachers, must know the philosophy of Kṛṣṇa consciousness so as not to be embarrassed and insulted when they preach.
*— *Śrīmad-Bhāgavatam *[[sb/6/1/38|6.1.38]]*
### 2. The basis of Kṛṣṇa conscious preaching and missionary activity is Bhagavad-gītā, Śrīmad-Bhāgavatam, Caitanya-caritāmṛta and Bhakti-rasāmṛta-sindhu:
In our Kṛṣna consciousness movement we have ... limited our study of Vedic literatures to *Bhagavad-gītā, Śrīmad-Bhāgavatam, Caitanya-caritāmṛta *and *Bhakti-rasāmṛta-sindhu. *These four works are sufficient for preaching purposes. They are adequate for the understanding of the philosophy and the spreading of missionary activities all over the world.
*— Cc. *Madhya *[[cc/madhya/22/118|22.118]]*
### 3. The preacher should study and preach Bhagavad-gītā:
Lord Caitanya has advised all His followers to go everywhere and preach the message of Lord Kṛṣṇa. Since this message is essentially *Bhagavad-gītā, *the preacher's duty is to study *Bhagavad-gītā *as it is understood by disciplic succession and explained by great sages and learned devotees. One should speak to the general populace in accordance with one's predecessors—*sādhu, guru *and *śāstras. *This simple process is the easiest method by which one can glorify the Lord.
*— *Śrīmad-Bhāgavatam* [[sb/4/16/3|4.16.3]]*