What a great read. What's interesting is that this was written in 1917. Right about the time when the WT was being born. He doesn't mention JW's directly but does mention the Millerites.
Sinclair leaves no doubt about how he feels about organized religion. For anyone waking up he gives a unique perspective inasmuch as he observes that all religions are basically the same. "institutions having fixed dogmas and "revelations", creeds and rituals, with an administering caste claiming supernatural sanction." (read GB)
He continues, "It is the thesis of this book that "religion" in this sense is a source of income to parasites, and the natural ally of every form of oppression and exploitation."
Didn't someone once write "religion is a snare and a racket?"