The most virulent type of offense surfaces when devotees harbor impersonalist views, especially the desire to become God. Svarupa Damodara Gosvami warned that in bad company even advanced devotees risk falling prey to the allurements of Mayavada philosophy. “The Mayavada philosophy presents such a jugglery of words that even a highly elevated devotee who has accepted Krsna as his life and soul changes his decision when he reads the Mayavda commentary on the Vedanta-sutra” (mahā-bhāgavata yei, kṛṣṇa prāṇa-dhana yāra, māyāvāda-śravaṇe citta avaśya phire tāṅra). [Cc 3.2.96]
This offensive mentality gradually drains piety and spiritual vitality from the devotees, leaving them with either a mere semblance of attachment or the inclination for self-worship (ahaigrahopasana).
In 1970 ISKCON experienced a situation that shows how dangerous the Mayavada philosophy is and how it can lead the devotees to offend even Srila Prabhupada. Somehow, four of Srila Prabhupada’s sannyasis got the notio that Srila Prabhupada was Krsna and began to preach this philosophy. When Srila Prabhupada heard about it, his reaction was uncompromising. Like a lightning bolt he expelled those sannyasis from the society. Only after they had repented, renounced their misconceptions, and begged forgiveness did Srila Prabhupada allow them to again serve in his society. Even though these particular sannyasis were some of the most influential and favored devotees in ISKCON, the contamination of impersonal philosophy is so dangerous that Srila Prabhupada took a drastic step to purge it from his movement.
Sivarama Swami. Suddha-bhakti Cintamani, ch. 13.