There is no possibility that a first-class devotee will fall down, even though he may mix with non devotees to preach-SP
Madhya 22.71 purport… The standard of devotion is also categorized in the same way. A neophyte believes that only love of Kṛṣṇa or Kṛṣṇa consciousness is very good, but he may not know the basis of pure Kṛṣṇa consciousness or how one can become a perfect devotee. Sometimes in the heart of a neophyte there is attraction […]