All devotees, especially preachers, must know the philosophy of Krsna consciousness so as not to be embarrassed and insulted when they preach

[kanupriya agarwal]

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.

SB 6.1.38, Translation and Purport

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Hare Krishna Hare Krishna Krishna Krishna Hare Hare Hare Ram Hare Ram Hare Ram Ram Ram Hare Hare