The signature of the Gra on the letter of excommunication opens an interesting question: Is it possible to worship Satan while believing one is worshiping G-d? It seems clear that this is true as we know from Sanhedrin page 63 that there is such a thing as idol worship that is not intended. And we know from the Rambam in the Guide that the Spirit of the World in not the same thing as God. So the issue of the excommunication is more severe and serious than people are aware of. [The Ari also brings this same theme in a few places]. It is no wonder that people joining that cult and thus worshiping the Devil believe they are being good religious Jews.
And this opinion of mine was apparently shared by the Gra and the sages of Musar [Reb Israel Salanter and his disciples] who rigorously excluded any mention of that cult. Clearly Rav Shach was also of this opinion. So I am not a lone voice of reason in the wilderness. The greatest sages of Israel agreed with me and yet their opinions are ignored.
And this opinion of mine was apparently shared by the Gra and the sages of Musar [Reb Israel Salanter and his disciples] who rigorously excluded any mention of that cult. Clearly Rav Shach was also of this opinion. So I am not a lone voice of reason in the wilderness. The greatest sages of Israel agreed with me and yet their opinions are ignored.
