I wanted to deal with this problem from the standpoint of Maimonides and Rosenzweig.
(2) If possible I would like also to go into the problem of זה לעמת זה עשה אלהים. That in every area of value there is an equal and opposite area of value that is its exact opposite, and yet externally looks exactly the same as the original authentic thing. This opposite is not just a lower level of the first, but rather the exact opposite. [That is: It looks like Torah and dresses up in clothing which seem Torah'dick, but the inner essence is of the Devil (Sitra Achra)--which is most of the religious world. The Gra already pointed out this problem but for some strange reason he was ignored and still is.]
(3) As for the first issue I would like to mention the Maimonian concept of the Giving of the Torah as being a one time event in history with no second upcoming event to supplant it, or take its place.
The Rambam (Maimonides) concept here is contained in the Guide for the Perplexed.
As Sunwall puts it: "Historically there is only one revelation defining absolute and transhistorical standards of human behavior and opinion, that of Moses from Sinai. Everything else throughout history which is not imitative of it is the product of reason, imagination, or madness."
So we learn Gemara to understand the the laws of the Holy Torah. What cults do is to give lip service to the Law of Moses, but to claim priority status for their leader's book where are written his delusions.
(4) As for the second issue , the best thing is to make an authentic Litvak yeshiva in one's neighborhood in order to have a place to learn genuine Torah -the Oral and Written Law in depth with Rav Shach's Avi Ezri, and Musar.