While you’re waiting for the second part of the interview with Fr. Daniel Sysoyev and Yuri Maximov (which is very close to being finished), contemplate some understandings on sects from some Russian points of view.
The essence of every sect consists in deviation from correct Orthodox religious-moral teaching, and the essence of schism consists in deviation from Orthodox-ecclesiastical leadership, that is, from Church discipline.
The inner causes for this deviation are (1) “unreasonable zeal” concerning salvation which stimulates the search for new ways and means of salvation, (2) conceit and pride causing discord, logomachy, and disunity, and (3) enthusiasm for various doctrines without appropriate leadership.
Fragment of Draft Variant of a Report of Metropolitan Gregory (Chukov) of Leningrad and Novgorod “On the Issue of the Struggle with Sectarianism” (July 22, 1945-April 10, 1946) Source
6.3. The Orthodox Church makes a distinct different between non-Orthodox confessions which recognize faith in the Holy Trinity and the God-Man Jesus Christ and sects which reject the fundamental Christian dogmas. Recognizing the right for non-Orthodox Christians the right for witness and religious education among groups of the population traditionally belonging to them, the Orthodox Church opposes every destructive missionary activity of sects.
Foundational Principles of the Relationship of the Russian Orthodox Church to Non-Orthodox (2000) Source